AU2004100293A4 - Soil Separators And Self-Watering Pots - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE

SPECIFICATION

INNOVATION

PATENT

No. Application Date:

APPLICANT:

ADDRESS:

INVENTOR:

ADDRESS:

Moss Products Pty Ltd 711 Clayton Road, Clayton South, Vic. 3169 Robert Michael WILSON 7 Compton Street, Beaumaris, Vic, 3169 ADDRESS FOR

SERVICE:

INVENTION TITLE: Paul A Grant and Associates PO Box 60, Fisher, ACT, 2611 Soil Separators and Self-Watering Pots ASSOCIATED

PROVISIONAL:

The following statement is a full description of this invention, including the best method of performing it known to us: TITLE: SOIL SEPARATORS AND SELF-WATERING

POTS

TECHNICAL

FIELD

This invention relates to molded plastic soil separators for use in plant-growing pots of the self-watering type and to self-watering pot assemblies incorporating such separators. The invention is particularly, but not exclusively concerned with the use of ceramic pots as part of such assemblies and with ceramic pots designed for use therewith.

BACKGROUND TO THE INVENTION Self-watering plastic pot assemblies for growing plants are well known and typically comprise a molded plastic pot having integral hollow legs with bottom openings and (ii) a water bowl in which the pot can be stood. Normally, the pot and bowl are clipped or snapped together to form a single unit that can readily lifted and transported. The hollow legs are either filled with the soil in the pot or with fabric wicks so water in the bowl is drawn upwards by capillary action through the legs into the bulk of the soil in the pot. The bowl serves as a water storage chamber and is usually arranged so that its rim is spaced from the bottom of the pot to allow water to be added directly to the bowl and to allow the level of water within the bowl to be seen after the pot and bowl have been coupled together.

While ceramic self-watering pot assemblies can be made to a similar design to the plastic pot assemblies, this is generally impractical. First, the pot legs would be fragile and highly likely to break during transport or use. Second, cheap ceramic pot assemblies suitable for plants cannot be manufactured with the precision needed to allow their bowls and pots to be coupled together to permit lifting or moving as a unit. The pots and bowls certainly cannot be clipped or snapped together like plastic self-watering pot assemblies. It is known, of course, to feed fabric wicks through holes in the base of a conventional ceramic pot and to stand the pot on suitable supports in a water bowl.

However, this is not very common because of the complication involved and because wicks tend to degenerate rather quickly under attack by soil microorganisms. Also, evaporation of water from the open bowl means that it must be filled often.

OBJECTIVE OF THE INVENTION It is therefore the general objective of this invention to provide soil separators suitable for use in ceramic (and other) plant-growing pots of the self-watering type, improved self-watering pot assemblies and improved ceramic pots for use in such assemblies.

OUTLINE OF THE INVENTION From one aspect, the invention comprises a molded plastic separator for use in converting a plant-growing pot into a self-watering one. The separator includes a generally horizontal soil-supporting platform having a flexible peripheral skirt and at least hollow supporting leg that is adapted to support the platform above the bottom of the pot so as to create a water chamber in the pot below the level of the platform. The bottom of the leg is open to the ingress of water from the chamber, while the top of the hollow leg opens out into the platform so as to permit ingress of soil into the leg from above the platform. The peripheral skirt extending around the platform is adapted, because of its flexibility, to make deflecting contact with the inner surface of the wall of the pot under the weight of soil on the platform to inhibit soil passing between the platform and the pot wall into the water chamber.

The platform of the plastic separator may include a series of annular steps extending upwards and outward toward said skirt so that the platform is concave. This stiffens the platform against collapse under the weight of soil in the pot while allowing it (along with the peripheral skirt) to vary in concavity to accommodate pots of varying size. The platform is preferably perforated to permit the passage of water vapor therethrough and to permit the growth of plant roots therethrough From another aspect, the invention involves a self-watering pot assembly which includes a pot and a separator of the type indicated above. The pot will normally be a ceramic one that has a water-proof lower portion without any bottom hole so that it is adapted to form a water chamber and the pot will have at least one side hole in the side wall of the lower portion with a lower lip. The moulded plastic separator is supported by its hollow leg or legs from the bottom of the pot so that the platform is above said lip and the peripheral skirt deflectingly contacts the inner wall of the pot above the lip to allow water to be poured directly into the water chamber through the side hole and to allow the level of water in the water chamber to be seen through the side hole.

The lower lip of each side hole in the pot is preferably out-turned to facilitate the pouring of water through the side hole into the pot and to enhance visibility of the water level in the chamber through the side hole. Particularly with ceramic pots, it is preferable for the pot's sides to taper outwardly and upwardly from the bottom so that such out-turned lips can be at least partially protected from contact when multiple pots of the same shape and size are arranged sideby-side.

Ceramic pots of this nature can be readily manufactured without the need to change the manufacturing methods or materials; they do not need to be dimensionally consistent or accurate and they need not cost any more than conventional ceramic flower pots. However, it is obviously important that the pots are either made without the conventional drainage holes in their bottoms or that these holes are plugged in a watertight manner.

It will be convenient to produce the plastic separator by injection moulding from thermoplastic materials such as LDPE [low density polyethylene], because complex forms can be readily produced at low cost. Thus, separators that have integral hollow legs, and/or a plurality of annular steps that rise from the center to the periphery and/or that are perforated and/or that provided with upturned flexible peripheral skirts can be readily formed by injection molding methods.

Similarly, separators for pots of any shape (in plan view) can be made, it not being necessary that the separator be circular (though that will certainly be the most common shape).

The number, size and placement of the legs will depend upon the diameter and volume of the separator, a separator for use with a small diameter pot may need only a single central leg; one for a medium diameter pot may have three or four legs, while one for a large pot may have five or more legs. As already noted, it is preferably that all legs are hollow and all have side openings or castellations at their lower ends to permit the ingress of water.

The use of a stepped and/or skirted separator platform not only stiffens the platform as mentioned above, but permits one separator to be used with a range of different sizes of pots and/or to accommodate pots that are not accurate in section. Indeed, an important advantage of the separators of the present invention is that they can be made to fit pots that are made to wide dimensional tolerances. When a skirted separator is used with a pot of about the maximum appropriate size, the skirt will be deflected upwards by the internal wall of the pot just above the level of the side hole(s). The weight of soil on the platform will then press and hold the skirt against the inside of the pot to form seal that stops soil from falling down between the periphery of the platform and the wall of the pot. When stepped and skirted separator is used with a pot having a lower portion of smaller section, or one that has a greater taper, the steps allow the platform to assume a concave shape under the weight of the soil while still presenting the skirt to the inside wall of the pot above the side hole(s) in a sealing manner.

DESCRIPTION OF EXAMPLE Having outlined the nature of the present invention, an example of a selfwatering ceramic pot assembly and two suitable separators will be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic sectional perspective view of the chosen selfwatering ceramic pot assembly that includes the first separator and is filled with soil and water.

Figure 2 is a perspective view from above of the second separator, which is of alternative design to that shown in the assembly of Figure 1.

Figure 3 is a perspective view from below of the separator of Figure 2.

With reference to Figure 1, the pot assembly 10 of the chosen example basically comprises a conventional ceramic pot 12 fitted with an injectionmoulded plastic separator 14 that divides the interior of the pot into an upper portion 16 containing soil 18 (shown cut-away) and a lower portion 20 that forms a water chamber and is shown containing water 22 having a surface level 24.

Pot 12 can be fired or unfired, glazed, painted or uncoated; it can be thrown, pressed or slip-cast from terracotta, clay or cementacious or other material. In this example, upper portion 16 is of substantially cylindrical shape and lower portion 20 is of a substantially conical shape, widening outwards and upwards.

Pot 12 has a rim 26, an upper wall portion 28, lower wall portion 30 and a flat water-tight base 32. Base 32 is preferably formed without any holes therethrough as shown in Figure 1 but, if a hole is provided (to allow the pot to be used in a conventional manner), it should be closed.

In this example, a single side hole 34 is formed in lower portion wall 30 in such a way as to provide a substantial outwardly projecting lower lip 36. Pot 12, hole 34 and lip 36 are preferably dimensioned so that: hole 34 and lip 36 are big enough to allow water to be easily poured into water chamber lip 36 extends outwards sufficiently to make the water level 24 in chamber 20 readily visible, and rim 26 and/or upper wall portion 28 are preferably large enough to protect lip 36 when pot 12 is arranged side by side with other similar pots (nt shown), or when it is arranged against a vertical wall (not shown).

In the example of Figure 1, separator 14 is injection-molded from LDPE to form a perforated and stepped circular platform 40 that has a flat central portion 42, four concentric rising steps 44 and a thin, flexible peripheral skirt 46. Integrally moulded with platform 40 are four hollow tapering legs, only three of which indicated at 48a, 48b and 48c are shown. Legs 48a and 48c are shown in section. Each leg has bottom openings 50 to allow ingress of water and each leg has an open top 52 that opens out into platform 40 to allow ingress of soil 18. For the sake of illustration, soil (indicated at 18a) is shown filling leg 48a only, leg 48c being shown as having no soil and being filled only with water (indicated at 22a).

From an inspection of Figure 1 it will be seen that pot 12 is about the optimum diameter for separator 14, the joint 54 between 46 and the remainder of platform 40 being close to lower wall portion 30 of pot 12 and steps 44 being generally horizontal. However, it will also be appreciated from an inspection of Figure 1 that separator 14 could be accommodated in a pot of substantially smaller diameter in the lower portion because steps 44 can flex upwardly (increasing the concavity of platform 40) without substantially affecting the seal between skirt 36 and lower wall 30 of pot 12. Similarly, it will be seen that separator 14 could be used with pots of somewhat larger diameter because outer steps 44 can bend downwards and because not all of skirt 46 is needed to form a seal with wall As already indicated above, the self-watering pot assembly 10 operates like a conventional self-watering pot of this type. That is, after separator 14 has been put in place, soil 18 has been loaded on top of separator 14 and water 22 has been poured into water chamber 20, water is conveyed by the soil 18a in hollow legs 48 by capillary action into the bulk of the soil 18. This keeps soil 18 moist for the benefit of any plant (not shown) growing therein.

Turning now to Figures 2 and 3, which show perspective views from above and below (respectively) of a separator 60 that differs somewhat from separator 14 of the example of Figure 1. As before, separator 60 is a unitary member injection-molded from plastics material, basically comprising a platform 62 and integral hollow legs 64. As before platform 62 is formed with annular steps 66 that rise from a flat central portion 68 toward an integral flexible peripheral skirt 70. Steps 66 are perforated with arcuate slots 72 that allow moisture and roots to pass through platform 62. In this example, however, separator 60 is intended for a relatively small pot (compared with that of Figure 1) and is therefore provided with only three hollow supporting legs 64 (instead of four as with separator 14) and with only three steps 66 (instead of four as with separator 14).

As in the case of separator 14, the tops of legs 64 open out into platform 62 at 74 (Figure 3) so as to allow soil to penetrate each leg. It will be seen that legs 64 are arranged so that they straddle the innermost one of steps 64 and, in fact, extend into platform center 68 and the second of steps 64. This has the advantage of further stiffening platform 62.

As shown in Figures 2 and 3, skirt 70 rises at a fairly steep angle with respect to the outermost step 64, as if it was located in a pot (not shown) of optimal size. When separator 60 is used with somewhat larger pots, skirt 70 will take up a more horizontal position. When it is used with somewhat smaller pots, the outermost step(s) 64 will be bent upwards along with skirt 70. Preferably, in the as-moulded state, skirt 70 lies closer to the horizontal than as shown in Figures 2 and 3. This allows the outer edge 76 of skirt 70 to touch the wall of such larger pots without having to be weighted by soil in order to do so.

As will be seen best from Figure 3, the bottom extremity 60 of each tapered hollow leg 64 is castellated to form spaced protrusions 78 and intervening gaps that allow water flow into the legs even though the bottom of legs 64 are resting on a flat surface. An annular internal flange 82 (see Figure 3) is included in the bottom of each leg for reinforcing purposes, leaving a central water passage 84.

It will be appreciated that, although the illustrated examples of plastic separators enable ceramic (and other) pots to be made self-watering in a simple, robust and cost-effective manner, many alterations and additions can be made to the illustrated examples of separators and pots without departing from the scope of the invention as defined by the following claims.

Claims (4)

1. A molded plastic separator for use in converting a plant-growing pot into a self-watering one, the separator comprising: a generally horizontal soil-supporting platform, at least one integral hollow leg extending downward from the platform and adapted to support the platform above the bottom of the pot and thereby form a water chamber in the pot below the level of said platform, said at least one hollow leg having a bottom end that is open to the ingress of water from the chamber and said leg having a top end that opens into the platform so as to permit ingress of soil into the leg from above the platform, and a flexible peripheral skirt extending around the platform adapted to make deflecting contact with the inner surface of the pot and to thereby inhibit the passage of soil supported by the platform into the water chamber.

2. A plastic separator according to claim 1 characterized in that: said platform comprises a series of annular steps extending upwards and outward toward said skirt so that the platform is of concave form, said separator thereby being stiffened against collapse under the weight of soil in the pot while being adapted to vary in concavity to accommodate pots of varying size.

3. A plastic separator according to claim 1 or claim 2 wherein the platform is perforated to permit the passage of water vapor therethrough and to permit the growth of plant roots therethrough.

4. A self-watering pot assembly comprising: a ceramic pot having a water-proof lower portion without a bottom hole and thereby adapted to form a water chamber and having a side hole in the side wall of said lower portion, said side hole having a lower lip, and a molded plastic separator of the type claimed in any preceding claim such that the leg or legs of said separator are adapted to support the platform of the separator from the bottom of the pot at a level above said lip and such that the peripheral skirt of the separator is adapted to deflect to contact the inner wall of the pot above the level of the lip so that water can be poured directly into the water chamber through the side hole and so that the level of water in the water chamber can be seen through the side hole. A ceramic pot for use in the self-watering pot assembly as claimed in claim 4 characterized in that: said lower lip of the side hole is out-turned to facilitate the pouring of water into the pot through the side hole and to facilitate the viewing of the water level in the chamber through the side hole, and the pot tapers outwardly and upwardly from the bottom so that said out-turned lip is at least partially protected from contact when multiple pots of the same shape and size are arranged side-by-side. Moss Products Pty Ltd By its Attorney Paul A Grant 13 April 2004