GB2088186A - Seed trays - Google Patents

Abstract

A seed tray has a plurality of compartments 1 comprising apertures extending through the tray, each aperture having an upper portion 2 of generally rectangular transverse cross-section and a lower portion 3 of generally circular transverse cross- section. In one embodiment, the upper portion joins directly to the lower portion. In another embodiment, an intermediate portion is provided, the transverse cross-section of which changes gradually from rectangular (adjacent the upper portion) to circular (adjacent the lower portion). <IMAGE>

Description

SPECIFICATION Seed trays This invention relates to seed trays or the like.

Such trays are sometimes referred to as propagating trays or plant trays. A known tray comprises individual compartments or recesses into which a growing medium is placed. Generally, a seed is placed in each compartment and when the seedling has grown sufficiently it is transplanted by removing the seedling with the growing medium from its compartment and planting the seedling with its roots still embedded in the medium. Thus, possible damage to the seedling and its roots is minimised.

The seed trays are commonly made of expanded polystyrene material. A known tray has compartments with flat sides, the compartments being square in transverse cross-section, with the sides tapering from a top opening to a bottom, drainage opening. The tapering sides permit easy removal of the seedlings and the growing medium from the compartments.

The object of the present invention is to provide an improved seed tray.

In accordance with the invention, there is provided a seed tray having a plurality of compartments comprising apertures extending through the tray, each of which comprises an upper portion of generally rectangular transverse cross-section and a lower portion of generally circular transverse cross-section.

The upper portion of each compartment is generally rectangular, in transverse cross-section, by which we mean that (in transverse crosssection) the two pairs of parallel, opposed sides are substantially at right angles, although the internal corners may, if desired, be rounded.

In one preferred arrangement, the upper portion of each recess comprises a top part the sides of which are non-tapering or only slightly tapering, and a bottom part of the sides of which taper substantially from the top part to the lower portion. In this arrangement, the lower portion preferably comprises a frusto-conical top part adjacent the upper portion and a cylindrical bottom part forming a drainage hole which opens to the bottom of the tray.

The lower portion of each compartment may terminate at a flat horizontal bottom shelf, in which is formed a drainage hole for the compartment, or it may terminate at the drainage hole itself. The drainage hole will generally be cylindrical. In the region where the compartment wall meets the flat bottom, it will be generally circular in transverse cross-section, and the area of transverse cross-section will be substantially smaller than the area of transverse cross-section of the upper portion of the compartment, i.e. the compartment tapers inwardly between the top and the bottom.

The upper portion of each compartment may join directly to the lower portion. More preferably, however, there is provided an intermediate portion between the upper and the lower portions, in which the transverse cross-sectional shape of the compartment gradually changes from generally rectangular (at the top) to generally circular (at the bottom), and also gradually tapers inwardly. This may be achieved by providing inwardly curving wall portions. In this way, each compartment may have a smooth wall with no vertical discontinuities (which can give rise both to manufacturing difficulties and to problems in use), the wall gradually changing the transverse cross-section of the compartment from generally rectangular at the top to generally circular at the bottom (i.e. at the horizontal bottom shelf if there is one, or otherwise at the bottom drainage opening of the compartment).In this arrangement, the upper portion will normally be shallow as may be the lower portion, so that the intermediate portion in which the transverse cross-sectional shape is transitional, extends for the greater part of the depth of the compartment. Indeed, in one such an arrangement each compartment comprises a generally rectangular open top and a generally circular and smaller open bottom, joined by an intermedate portion in which there is a gradual transition in cross-section between the top and the bottom.

It is to be understood that, whilst in certain embodiments of the invention, it will be possible to identify the exact extent of the upper, lower and any intermediate portions of the compartments, in other embodiments the transitions between portions may be smooth and continuous disallowing of exact location of the change from one portion to another.

Two preferred embodiments of seed tray in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a plan view of a first tray from above; FIGURE 2 is a part cross-sectional view taken on line Il-Il of Figure 1; FIGURE 3 is an end view of the first tray; FIGURE 4 is a fragmentary bottom view of the first tray; FIGURE 5 is a plan view of the second tray from above; FIGURE 6 is a part cross-sectional view taken on line Il-Il of Figure 5; FIGURE 7 is a partial end view of the second tray; FIGURE 8 is a fragmentary bottom view of the second tray in which the compartments are as in Figure 6 but which has a modified underside; and FIGURE 9 is a part section on the line A-A of Figure 5.

tIgure O.

Referring to Figures 1 to 4, the first seed tray comprises a plurality of compartments 1 arranged in parallel rows. As illustrated there are forty compartments arranged in five rows, but any desired number could be used. Each compartment comprises an aperture having an upper portion 2 of rectangular cross-section, preferably square, and a lower portion 3 of circular cross-section.

The upper portion 2 comprises a top part 4 having sides 5 which are non-tapering, or which taper only slightly, for example of the order of 30, and a major bottom part 6 the sides 7 of which taper substantially, as illustrated. The top part 4 is shallow, of preferably of the order of 1/4 to 1/5 of the total depth of the tray, whereas the bottom part 6 extends over a substantial part of the depth of the tray, for example 1/2 to 2/3 of the total depth.

The lower portion of each compartment is also relatively shallow and comprises a cylindrical bottom part 8 which opens into the bottom surface 9 of the tray and a generally frusto-conical upper part 10 which interconnects the cylindrical part 8 with the rectangular lower part 6.

Around the periphery of its upper surface the tray preferably has a lip 11 and at its bottom corners there are projections 1 2 which hold the bottom openings of the compartments from the surface on which the tray is standing to permit drainage from the compartments.

In order to reduce the amount of material used for the tray, the sides 1 3 are preferably sloping and recesses (not shown) may be provided in area 14 between the compartments at the bottom of the tray. However, the sides 13 may be vertical, i.e. perpendicular to the bottom surface.

Referring to Figures 5 to 9, the second seed tray comprises a plurality of compartments 1 arranged in parallel rows. As illustrated there are forty compartments (not all are shown in Figure 5) regularly arranged in five rows, but any desired number could be used. Each compartment comprises an aperture having an upper portion 2 of generally rectangular cross-section, preferably generally square, and a lower portion 3 of generally circular cross-section.

The upper portion 2 comprises a very shallow region 4 having correspondingly short sides 5 which are non-tapering, or which taper only slightly, for example of the order of 30.

The lower portion of each compartment is also relatively shallow and comprises a cylindrical bottom part 8 which abuts a horizontal shelf surface 9 of the tray, in which is formed drainage hole 10.

Extending between upper portion 2 and lower portion 3 is intermediate portion 6 of the walls of which (on the section of Figure 6) are curved inwardly a radius R about centre C. On the section A-A (Figure 9), the walls are generally straight, or slightly curved, and they extend from the corners of the upper portion. In transverse cross-section, the portion 6 gradually changes from generally rectangular to generally circular as it travels from upper portion 2 to lower portion 3.

Around the periphery of its upper surface the tray preferably has a lip 11 and at its bottom corners there may be projections (not shown) which hold the bottom openings 10 of the compartments from the surface on which the tray is standing to permit drainage from the compartments.

In order to reduce the amount of material used for the tray, the sides 1 3 are preferably sloping and recesses may be provided in areas 14 (Figure 6) and are shown as 16 in Figure 8 between the compartments at the bottom of the tray. However, the sides 13 may be vertical, i.e.

perpendicular to the bottom surface.

The above-described trays have the advantages that because of the gradually tapering sides, the growing medium and seedling are readily removed either by pulling the seedling from above or by pushing the medium from below, the seedling and its roots then being in a good, undamaged condition for transplanting. The depth and shape of the compartments allows good root growth, with the roots growing downwardly towards the bottom opening. The risk of the seedling being "pot bound" is thus minimised. Furthermore, the relatively large cross-sectional area of the top part 4 permits easy pianting of seeds and allows substantial initial lateral root growth. The provisions of a bottom shelf reduces the incidence of growing medium falling out of the compartment on loading for seeding.

Claims (13)

1. A seed tray having a plurality of compartments comprising apertures extending through the tray, each of which comprises an upper portion of generally rectangular transverse cross-section and a lower portion of generally circular transverse cross-section.

2. A tray according to claim 1, wherein the upper portion of each recess comprises a top part the sides of which are non-tapering or only slightly tapering, and a bottom part the sides of which taper substantially from the top part to the lower portion.

3. A tray according to claim 2, wherein the top part of the upper portion is shallow and extends up to about 4 of the tray depth, and the bottom part is deeper and extends up to about 32 of the tray depth.

4. A tray according to claim 1, 2 or 3, wherein the lower portion comprises a frusto-conical top part adjacent the upper portion and a cylindrical bottom part forming a drainage hole which opens to the bottom of the tray.

5. A tray according to claim 1, wherein each aperture also comprises an intermediate portion which joins the upper portion to the lower portion.

6. A tray according to claim 5, wherein the transverse cross-sectional shape of the intermediate portion gradually changes from generally rectangular (adjacent the upper portion) to generally circular adjacent the lower portion, the intermediate portion also gradually tapering inwardly from top to bottom.

7. A tray according to claim 5 or 6, wherein the lower portion comprises a shelf in which is formed a drainage hole opening to the bottom of the tray, said intermediate portion terminating at said shelf.

8. A tray according to claim 5, 6 or 7, wherein the intermediate portion extends for up to 9 of the depth of the tray.

9. A tray according to any preceding claim wherein the upper portion of each compartment has a square transverse cross-section.

10. A tray according to any preceding claim which has a lip around the periphery of its upper surface.

11. A tray according to any preceding claim which has one or more projections from the bottom surface to hold the bottoms of the compartments above a support surface to facilitate drainage from the compartments.

12. A tray according to any preceding claim, wherein recesses are provided in the bottom of the tray between the compartments.

13. A seed tray substantially as herein described in Figures 1 to 4, or 5 to 9 of the accompanying drawings.