It is known to provide containers, isolated from the underlying soil or other surface, for growing plants of many types. Isolation of the growing medium allows precise control and optimization of the growing conditions for intensive cultivation of a given plant. The isolation is also useful in preventing propagation of diseases.

Growing containers in use today are of two main types: rigid containers typically made from expanded polystyrene foam; and elongated troughs folded from strips of flexible material, most commonly, polypropylene.

The latter option is illustrated in Figures 1 and 2. The strip 10 of flexible material is supplied in a flat configuration, typically as a roll 12. At the site at which the trough is required, the required length of strip 10 is unrolled and cut. The strip is then folded along pre-formed fold lines 14 to form sides 16 and a base 18.

The folded configuration is then fixed by one of a number of techniques. In the example shown, cords 20 are strung through holes 22 in sides 16 and are locked in place by pegs 24 which clip onto sides 16.

The elongated trough structure has a number of important advantages over polystyrene containers. It is cheaper to produce, and can be compactly packaged in rolled form for low cost transportation and storage. The polypropylene material is also harder wearing and is stable both under steam and chemical disinfection techniques of types which cannot be used for polystyrene.

Despite these numerous advantages, polystyrene containers are still preferred in some contexts because of their cellular nature. Since each container is isolated from adjacent containers, incidence of diseases are usually limited to individual containers and do not readily spread. In contrast, the elongated trough

structures are at risk of propagating diseases through flow of irrigation fluid along the length of the trough.

There is therefore a need for an apparatus and system for sub-dividing trough type growing containers into isolated cells so as to prevent transmission of water borne diseases between the cells.

SUMMARY OF THE INVENTION The present invention is an apparatus and method for subdividing elongated growing troughs into isolated cells to prevent transmission of water borne diseases therebetween.

According to the teachings of the present invention there is provided, a divider for subdividing an elongated growing trough into isolated cells such that liquid-borne diseases are not transmitted between the cells, the trough having a base and two side walls and being prepared so as to provide first and second cell ends, the divider comprising: (a) a water-impermeable dividing wall to be deployed transversely so as to form a barrier between the first and second cells; (b) a first set of attachment features associated with a first side of the dividing wall and configured for attaching to the first cell end; and (c) a second set of attachment features associated with a second side of the dividing wall and configured for attaching to the second cell end.

According to a further feature of the present invention, the first and second sets of attachment features each include a base wall portion and two side wall portions projecting substantially perpendicular from the dividing wall.

According to a further feature of the present invention, there is also provided at least one drainage hole located on each side of the dividing wall so as to prevent accumulation of liquids adjacent to the first and second cell ends.

According to a further feature of the present invention, the divider is a folded structure formed from a single blank of sheet material.

There is also provided according to the teachings of the present invention, a blank, foldable to form a trough divider for use in subdividing an elongated

growing trough into isolated cells such that liquid-borne diseases are not transmitted between the cells, the blank comprising a substantially rectangular sheet of flexible material having a first dimension defined as its length and a second dimension defined as its width, the sheet being subdivided for ease of reference along boundaries parallel to the width into a front portion, an intermediate wall-forming portion and a rear portion, and along boundaries parallel to the length into a right margin, a central portion and a left margin, the sheet having a pair of similar elongated cuts running substantially parallel to the length along the boundaries on both sides of the central portion, the elongated cuts extending along the entirety of the intermediate wall-forming portion, the sheet further featuring a plurality of fold lines formed so as to facilitate folding of the sheet along the fold lines, the fold lines extending along the boundaries parallel to the width, along uncut portions of the boundaries parallel to the length, and subdividing the intermediate wall-forming portion along a line parallel to the width.

According to a further feature of the present invention, both the front and the rear portions feature at least one attachment hole through each of the left and right margins.

According to a further feature of the present invention, both the front and the rear portions feature at least one drainage hole.

There is also provided according to the teachings of the present invention, a method of subdividing an elongated growing trough into isolated cells such that liquid-borne diseases are not transmitted between the cells, the trough having a base and two side walls, the method comprising: (a) preparing the trough to provide first and second adjacent cell ends; (b) providing a divider having: (i) a water-impermeable dividing wall to be deployed transversely so as to form a barrier between the first and second cells; (ii) a first set of attachment features associated with a first side of the dividing wall and configured for attaching to the first cell end, and (iii) a second set of attachment features associated with a second side of the dividing wall and configured for attaching to the second cell end; and

(c) attaching the first cell end to the first set of attachment features and the second cell end to the second set of attachment features so as to form a cell structure having two adjacent but isolated trough cells.

There is also provided according to the teachings of the present invention, a blank, foldable to form an end piece for use in terminating an elongated growing trough, the blank comprising a sheet of flexible material including: (a) a substantially rectangular front portion with a first dimension defined as its length and a second dimension defined as its width, the front portion being subdivided for ease of reference along two boundaries parallel to the length into a right margin, a central portion and a left margin, the front portion also having a rear edge; (b) a central extension connected to the rear edge of the central portion and extending from the central portion in a direction parallel to the length; (c) a right tab connected to the rear edge of the right margin and extending from the right margin in a direction parallel to the length; and (d) a left tab connected to the rear edge of the left margin and extending from the left margin in a direction parallel to the length, the sheet further featuring a plurality of fold lines formed so as to facilitate folding of the sheet along the fold lines, the fold lines extending along the rear edge, along the boundaries parallel to the length, and subdividing the central extension along two spaced-apart lines parallel to the width.

According to a further feature of the present invention, a length of the central extension is at least about 21/2 times a width of the left and right tabs.

According to a further feature of the present invention, the two spaced-apart lines parallel to the width are respectively spaced from the rear edge by at least about once and about twice the width of the left and the right tabs.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: FIG. 1 is a schematic isometric view of a roll of flexible material for forming an elongated growing trough;

FIG. 2 is a schematic isometric view of the material of Figure 1 configured as an elongated growing trough; FIG. 3 is a plan view of a blank for use in forming a divider, constructed and operative according to the teachings of the present invention, for subdividing a growing trough; FIGS. 4 and 5 are schematic isometric views showing two stages of folding of the blank of Figure 3 to form a divider; FIG. 6 is a schematic isometric view of the divider of Figure 5 used to subdivide an elongated growing trough; FIG. 7 is a plan view of a first variant of the blank of Figure 3; FIG. 8 is a plan view of a second variant of the blank of Figure 3; FIG. 9 is a plan view of a blank for use in forming an end-piece, constructed and operative according to the teachings of the present invention, for closing an end of a growing trough; FIGS. 10 and 11 are schematic isometric views showing two stages of folding of the blank of Figure 9 to form an end-piece; and FIG. 12 is a schematic isometric view of the end-piece of Figure 11 used to close an end of an elongated growing trough.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is an apparatus, namely, dividers or end-pieces, and a corresponding method for subdividing elongated growing troughs into isolated cells.

The principles and operation of dividers and end-pieces according to the present invention may be better understood with reference to the drawings and the accompanying description.

Referring now to the drawings, Figure 3 shows a blank, generally designated 30. Blank 30 is foldable to form a trough divider for use in subdividing an elongated growing trough into isolated cells, as will be described below.

Generally speaking, blank 30 is a substantially rectangular sheet of flexible material, having a first dimension 32 defined as its length and a second dimension 34 defined as its width. For ease of reference, the sheet is subdivided along boundaries parallel to width 34 into a front portion 36, an intermediate wall- forming portion 38 and a rear portion 40. Similarly, the sheet is divided along boundaries parallel to length 32 into a right margin a, a central portion b and a left margin c. Thus, by regarding the area of sheet 30 as a 3x3 grid, reference can be made to nine different regions, i. e., 36a, 36b, 36c, 38a, etc.

Sheet 30 has a pair of similar elongated cuts 42 running substantially parallel to length 32 along both sides of the central portion b, and extending along the entirety of intermediate wall-forming portion 38. In other words, cuts 42 extend along the boundaries between region 38b and both 38a and 38c. Sheet 30 also features a number of fold lines formed so as to facilitate folding of the sheet.

Specifically, two fold lines 44 extend along the boundaries parallel to width 34, four more fold lines 46 extend along uncut portions of the boundaries parallel to the length 32, and an additional fold line 48 subdivides intermediate wall-forming portion 38 along a line parallel to width 34.

Sheet 30 is preferably cut from a strip of material of the type used to form the trough. In fact, production of sheet 30 from a section of trough strip of the type with which the divider is to be used is particularly advantageous. Besides ensuring compatibility and size matching, the longitudinal fold lines 46 are effectively ready made since they correspond to the position of the fold lines produced along the strip as it is extruded. The remaining cuts and fold lines are typically formed by stamping with a suitably prepared die or other conventional techniques as are known in the art.

Preferably, both front and rear portions 36 and 40 feature at least one drainage hole 52 in central portion b. The drainage holes may be located on one of the boundaries, and advantageously, may be at the junction of fold lines 44 and 46, as shown. In this position, holes 52 also act as terminal holes for cuts 42, serving to spread any applied forces so as to prevent tearing of the material.

Optionally, both front and rear portions 36 and 40 feature at least one attachment hole 54 through each of the left and right margins a and c.

The sequence of folding blank 30 is illustrated in Figures 4 and 5. First, folds 44 are both folded in a first direction and fold 48 is folded in the opposite direction to form a width-ways ridge 50 as shown in Figure 4. Cuts 42 separate ridge 50 into three sections designated 50a, 50b and 50c.

Then, right and left margins a and c are folded up along fold lines 46. As they are folded up, the marginal ridge sections 50a and 50c are inserted into the open sides of central ridge section 50b. These serve as tabs which secure the front and rear marginal regions 36a, c and 40a, c in perpendicular relation to front and rear central regions 36b and 40b to form side walls.

Once folded into shape, sheet 30 is ready to function as a divider.

Specifically, the principal feature required of a divider according to the present invention is that it provides a water-impermeable dividing wall which can be deployed in transverse relation to the length of a trough to form a barrier between two cells. This function is provided by central ridge section 50b. In addition, the side and base portions formed by front and rear portions 36 and 40 serve as sets of attachment features projecting substantially perpendicular from each side of the dividing wall to facilitate attachment to adjacent ends of trough cells.

The use of divider 30 is shown in Figure 6. Firstly, the trough 10 is prepared so as to provide first and second adjacent cell ends 60 and 62. Typically, this is done by severing the trough at the position at which a divider is required, although separate pieces of trough may be juxtaposed to the same effect. Alternatively, effective"cell ends"may be generated by stripping away sides 16 from a section of the trough or otherwise modifying the trough structure so as to accommodate divider 30 without severing the trough completely. Thus, it should be appreciated that the word"end"as used herein does not necessarily imply disconnection.

First and second cell ends 60 and 62 are then attached to the side and base portions on opposite sides of the barrier wall 38b, thereby forming a cell structure having two adjacent but isolated trough cells. The attachment may be achieved by

any desired method. By way of example, the ends may be tied to the side portions of the divider by use of holes 54 and holes 22. The attachment shown here has the cell ends positioned interior to the divider attachment regions. However, this configuration may be reversed. The inherent flexibility of the material used is typically sufficient to accommodate either configuration.

It should be appreciated that the subdivision shown here is effective to prevent transmission of liquid-borne diseases between the cells. Even if the attachment of each cell end to the divider is far from water-tight, the presence of a lateral water-tight barrier 38b combine with adjacent drainage holes 52 ensures that irrigation fluids released into each cell drain out of the cells rather than passing between the cells. In various circumstances, the barrier may also be valuable for preventing movement of solid materials between the cells.

Turning now to Figures 7 and 8, these show two variants of blank 30 designated 64 and 66, respectively. Blank 64 is essentially similar to blank 30 in structure and use, differing only in that the marginal regions of the intermediate wall-forming portion 38a and 38c are shaped to facilitate easy folding of the blank.

Specifically, the inner edges of these regions where fold line 48 reaches cuts 42 are cut away. Similarly, the outer border of these regions adjacent to fold line 48 are also cut away. The effect of these cut-outs is that, when folded to form a ridge, the tabs formed by the side portions of ridge 50 have cropped corner. This facilitates insertion of these tabs into the open sides of the central portion of the ridge during folding.

Blank 66 is again similar to blank 30 except that it produces a reduced height barrier. This structure may be preferred in applications where mechanized processing requires all irrigation tubes and the like to be mounted below the level of the edges of the trough.

It should be appreciated in this context that the height of the barrier of the trough divider of the present invention may be a small fraction of the depth of the trough. Since the dominant movement of fluids within the growing medium is vertically downwards under the influence of gravity, the primary requirement for

isolation of drainage fluids is that the barrier prevents flow between the cells of fluids accumulated adjacent to the base of the trough. Thus, even a barrier of between about 10% and about 30% of the trough height may be fully effective to prevent transmission of fluid-borne diseases between adjacent cells.

Clearly, because of the geometry of the folded divider construction, the width of the marginal regions of the intermediate wall-forming portion 38a and 38c must be. no greater than, and typically substantially equal to, the height of the barrier. The height of the barrier, in turn, corresponds to half of the length of the intermediate wall-forming portion 38. Thus, in the full height implementation of blank 30 shown above, the length of the intermediate wall-forming portion 38 is twice the height of the trough.

In order to accommodate the reduced height barrier of blank 66, the outer edge of the marginal regions of the intermediate wall-forming portion 38a and 38c is cut back to reduce their width to equal the intended height. The length of the intermediate wall-forming potion is also reduced to twice the intended height. In this manner, it is possible to achieve any height of barrier desired.

Clearly, one or both of the cut-out features of blank 64 may be used together with the reduced-height barrier of blank 66 if desired.

Turning now to the structure of end pieces according to the present invention, these will now be described with reference to Figures 9-12. Figure 9 shows a blank, generally designated 70, constructed and operative according to the teachings of the present invention, foldable to form an end piece for use in terminating an elongated growing trough.

Generally speaking, blank 70 is formed from a sheet of flexible material having a substantially rectangular front portion 72 with a first dimension 74 defined as its length and a second dimension 76 defined as its width. Front portion 72 is subdivided for ease of reference along two boundaries 78 parallel to the length into a right margin 72a, a central portion 72b and a left margin 72c. Front portion 72 also has a rear edge 80. The sheet further includes a central extension 82 connected to rear edge 80 of central portion 72b and extending therefrom in a

direction parallel to length 74. A right tab 84 and a left tab 86 are connected to the rear edge of right and left margins 72a and 72c, respectively, and extend therefrom in a direction parallel to length 74. A plurality of fold lines, formed so as to facilitate folding of the sheet, extend along rear edge 80, boundaries 78, and subdivide central extension 82 along two spaced-apart lines 88 and 90 parallel to width 76.

Preferably, the length of central extension 82 is at least about 21/2 times the width of left and right tabs 84 and 86. This allows fold lines 88 and 90 to be spaced from rear edge 80 by at least about once, and about twice, the width of the tabs, respectively.

Figures 10 and 11 illustrate the steps of folding blank 70. First, margins 72a and 72c are folded up and tabs 84 and 86 are folded inwards so as to be aligned vertically above rear edge 80 (Figure 10). Then, central extension 82 is folded up along rear edge 80, back downwards at fold line 88, and horizontally at fold line 90, such that the distal section of central extension 82 lies flush against central portion 72b (Figure 11).

The end piece is then ready to receive an end of an elongated trough (Figure 12), either internally or externally. The end piece may be attached to the trough by any appropriate technique. The folded state of the end piece is maintained by the weight of either the trough itself or of the growing medium contained thereby against the folded end of central extension 82.

It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the spirit and the scope of the present invention.