PIVOTALLY LINKED RIGID CELL CHAINS

Abstract: Apparatus for propagation of plant seedlings including a cell chain comprising a series of cells (12) rigidly connected to form a group of aligned cells (10, 11) each group being connected in pivotal relation to another group by a link cell (121) to form a continuous chain of cells able to be mechanically handled by transport devices or concertined into a solid block of cells having little or no wastage of space.

Description: The present invention relates to connected individual cells intended for use in the mechanized propagation of seeds and the handling of plants propagated therein. In particular the invention relates to a cell as described in our Australian Patent Specification No. 516,117. These connected individual cells are commonly known as "cell chains". Cell chains are known wherein the cells are each tubular cylindrical constructions of substantially uniform cross-section with pivot connections formed between adjacent cells. These chains are moved between desired locations by drive sprocket wheels engaging essentially between the tubular cells with the open face of the cell directed upwardly to receive propagating material and a seed. While these cell chains are effective in operation they do suffer from certain practical disadvantages. Cell chains of this type because of their pivot arrangements between cells are stored in a circular spiral manner which take up considerable space both between individual cells and by the fact that a circular array of cells leaves substantial areas which cannot be occupied by cells. U.S. Patent Specification No. 4,167,911 discloses a plurality of individual cells, each of which is joined to the next adjacent cell by a thin, deliberately weakened paper or film connector. Not only are the connectors formed of weakened paper or film, but the cells themselves are formed of paper of the kind that is rottable or degradable, thereby enabling each individual cell to be separated from its adjacent cells and planted along with the seedling and its propagating medium. The disclosure is therefore such as to provide a plurality of containers which are initially linked by a weak connecting link but are subsequently separated and therefore consumed during seedling planting. The objective of the present invention is therefore to provide a reusable cell chain arrangement which will overcome or substantially minimise the aforementioned disadvantages associated with the known arrangements. Accordingly, the present invention provides a device for use in propagating plants comprising a plurality of open top individual cells joined to one another in an elongate row, said device being characterised in that the open top individual cells are held together in a rigid group (10) having opposed ends, first hinge means (12') carried at one end of said group (10), second hinge means (20, 21b) carried at an opposite end of said group (10), the first hinge means (12') at said one end of said group (10) being engageable with the second hinge means (20, 21b) of a like said group (11) to form a hinge connection (13) to enable pivotal coupling of said groups together whereby said first and second hinge means (12', 20, 21b) enables said one group (10) to pivot relative to an adjacent said like group (11) when interconnected in at least one direction through an arc of such length as to locate said one group (10) and said adjacent like group (11) substantially parallel to one another in side by side relation. Preferably, the individual cells in each group of cells are arranged in a straight line and the arrangement is such as to allow groups of cells to lie side by side in storage positions to make up a rectangular array of individual cells. In a further aspect of the invention, there is provided a cell chain including a plurality of containers for holding seeds or seedlings and propagating medium therein, the containers being interconnected by at least one link formed and located in such a way that a tooth of a toothed driving means may interengage the link and/or the containers for moving the cell chain from one point to another. The cross sectional shape of the containers may vary from circular, hexagonal, square or the like depending upon the desired mode of stacking and use of the invention, and the invention is not limited to any specific container shape. The chain can be easily produced as a plastics moulding. The containers may be formed with a bottom or alternatively, with inwardly tapered walls to prevent loss of soil therein. The containers may be shaped with hexagonal cross section thereby facilitating close stacking in straight lines. The cell chain may consist of a series of cells or plant compartments rigidly connected to form rigid groups containing a number of cells. Each group may be pivoted at either end using a link cell which will allow the previous and the following group to pivot about each other. In this way a continuous chain of alternating cell groups and links can be concertined into a solid block of cells to allow ease of handling and storage. The cell chain may be broken at any point where a link cell exists. The plant cells may vary in shape and size between derivatives of the cell chain. Some possibilities include conical shapes, cylinders and tapered hexagons. Provision can be made between each cell for engagement with a toothed driving means when the chain is straightened into a single strand. The link cell is uniquely designed to allow the rigid cell groups to hinge in either direction but still allow the cells to nest against each other to form a pack of hexagonal cells to appear as a solid sheet of honeycomb. The unique feature of the product is that in the packed configuration the container forms a rectangular mass able to maximize the use of space and fit in with standard horticultural practice in existing glass houses. When hinged apart (or straightened) the pack transforms into a single line of hinged cell groups of hexagonal cells, able to be mechanically handled at high speed in single file to select and transplant the soil block (plug) and plant at high speed. The invention may be better understood from the following description of preferred embodiments given in relation to the accompanying drawings. In the drawings:- Figure 1 is a perspective sketch of a hinge section between groups of connected cells of a first preferred embodiment. Figures 2a and 2b are plan views demonstrating schematically the 'wrapping' action of the cell chain to form a solid tray. Figure 3 is a plan view of rigid groups of cells forming a concertina. Figures 4a, 4b and 4c show elevations of a rigid cell chain group. Figures 5a, 5b and 5c show elevations of a cell chain link. Figure 6 is a bottom perspective view showing a hinge connection region in greater detail. Referring to Figures 1, and 4 a, b and c there is partially shown two groups 10, 11 of rigidly connected individual plant propagation cells 12 connected by a hinge element 13. Each of the cells has a polygonal, preferably regular/hexagonal open upper face 14 with a hollow body 15 tapering downwardly to a drainage opening 16 in the base of the cell. The drainage opening 16 comprises a restricted passage 17 together with a widening lower section 18. Each group of cells 10, 11 comprise cells 12 arranged rigidly in line. The number of cells in each group may be variable. The last cell 12' in each group has a curved outer face 19 allowing for pivoting movement of the group relative to the hinge element 13 as will hereinafter be explained. The other end of the group includes a pivot connecting collar 20 enabling the group to be hingedly connected to the hinge element 13. The hinge element 13 is shown in greater detail in Figures 5 a, b and c. The hinge element preferably comprises a single propagation cell 21 with a connecting hinge collar 22 equivalent to the collar 20 of the cell groups. Thus a double pivot hinge is formed between the adjacent cell groups 10, 11. The rigid element 12 has stop means 27, 28 arranged to limit pivoting movement but permitting pivoting in both directions from the centre line of the rigidly connected cells to a degree sufficient to allow the groups of cells to lie adjacent one another in a stcorage position. As is apparent from the Figures, the individual cells 12 are interconnected in each group by a pair of rigid webs 25, 26. The polygonal upper face of the cells are so arranged whereby adjacent groups of cells are adapted to nest into one another with substantially no space between adjacent cells. In this manner a substantially rectangular array of cells can be formed in a storage position with minimum wastage of space. There may also be provided lugs or other extending projections from between the rigid connecting webs 25, 26 to locate between adjacent webs 25, 26 of a second group of propagation cells when the respective groups are positioned next to one another in a storage position. This arrangement locks the groups together so that in the storage position the open faces 14 of the individual cells are all ensured to be located in the same plane. This is best shown in Figures 2 a, b and 3. Figure 6 shows a slightly modified form of the invention comprising a number of rigidly interconnected individual cells 12 having essentially hexagonal upper faces 14 forming rigid groups of in line cells 10 and 11. A hinge element 13 joins the two groups. The hinge element comprises a cell 21 having a base section 21 press fitted but retained for pivoting movement within a retaining ring 21b rigidly formed at the end of the group 10 of the rigidly connected cells. The hinge element 13 further includes a ring or collar 13' extending laterally from the cell 21 which press fits in a pivoting manner over the base section 12b of the end cell 12' of the rigid group of cells 11. In this manner, a double hinge connection is formed. A pair of web structures 25 and 26 hold the cells 12, 12' together and lateral projections 26' are provided between the webs and extending outwardly beyond the webs to be located within the space 26b between the webs when the groups of cells are folded to be nested into one another in side by side relationship. As will be seen in Figure 6, a pair of stop projections 27 (only one of which can be seen) are provided on a flange section 27' of the rigid element 12. The stop projections limit the rotation of the hinge element to substantially equal amounts on either side of the centre line of the group of cells 10 and 11. In other respects the embodiment of Figure 6 is essentially similar to the embodiment illustrated in Figures 1 to 5.

Claims: A device for use in propagating plants comprising a plurality of open top individual cells joined to one another in an elongate row, said device being characterized in that the open top individual cells are held together in a rigid group (10) having opposed ends, first hinge means (12') carried at one end of said group (10), second hinge means (20, 21b) carried at an opposite end of said group (10), the first hinge means (12') at said one end of said group (10) being engagable with the second hinge means (20, 21b) of a like said group (11) to form a hinge connection (13) to enable pivotal coupling of said groups together whereby said first and second hinge means (12', 20, 21b) enables said one group (10) to pivot relative to an adjacent said like group (11) when interconnected in at least one direction through an arc of such length as to locate said one group (10) and said adjacent like group (11) substantially parallel to one another in side by side relation. A device according to claim 1 characterized in that said one group (10) is interconnected to said adjacent group (11) by said hinge connection (13). A device according to claim 2 characterized in that said hinge connection enables said adjacent group (11) to extend in prolongation of said one group (10) along a straight line. A device according to claim 2 characterized in that the cells (12) of said groups (10, 11) are staggered when said groups (10, 11) are pivoted to extend alongside and substantially parallel to one another. A device according to claim 2 characterized in that said hinge connection (13) enables said one group (10) to pivot relative to the adjacent said group (11) in either of two opposite directions to locate said one group (10) and said adjacent group (11) in substantially parallel, side-by-side relation. A device according to claim 2 characterized in that said hinge connection (13) includes limit means (27, 28) for limiting relative pivotal movement of said adjacent groups (10, 11). A device, according to claim 2 characterized in that each of said groups (10, 11) has an endmost cell (12') formed with an arcuate external surface (19). A device according to claim 7 characterized in that said endmost cell (12') is at one end only of the associated group (10, 11). A device according to claim 2 characterized in that said hinge connection (13) includes a collar (20, 21b) in which a lower end of an endmost one of said cells (12') is rotatably accommodated. A device according to claim 9 characterized in said hinge conncection (13) includes a collar (22) carried by and projecting from a cell (21) having its lower end rotatably accommodated in said collar (20, 21b). A device according to claim 1 characterized in that said first hinge means comprises a collar (20, 21b) extending beyond one end of said first group (10). A device according to claim 11 characterized in that hinge means comprises a cell (12') having a sleeve at its lower end of such size as rotatably to be accommodated in said collar (20, 21b). A device according to claim 11 characterized in that said first hinge means further includes a hinge element comprising a cell (21) having a lower end pivotably engaged with said collar (20, 21b) and a second collar (22) extending from said cell (21). A device according to claim 1 characterized in that a coupling element (13) is pivotably connected to said second hinge means (20, 21b), said coupling element being adapted for pivotal connection to the first hinge means (12') of a like said group. A device according to any one of claims 1 to 14 characterized in that said one group (10) includes at least one engagement member (26') co-operable with retainer means (25, 26) of an adjacent said like group when said groups are arranged parallel to one another in side-by-side relation.

Inventors: WILLIAMES, GEOFFREY ALAN
Applicants: WILLIAMES HI-TECH INTERNATIONAL PTY. LIMITED
Application year: 1986
Main classification: A01G9
IPC codes: A01C1, A01G9