WO2007071941A1

WO2007071941A1 - Planter

Info

Publication number: WO2007071941A1
Application number: PCT/GB2006/004706
Authority: WO
Inventors: Peter Barnes; William Brett Allen
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-12-21
Filing date: 2006-12-15
Publication date: 2007-06-28
Anticipated expiration: 2008-06-21
Also published as: GB2433408B; GB0526153D0; GB2433408A

Abstract

The planter has a base (2) which is surrounded by an upstanding side wall (3) to define a planting space (8). A gas tight air chamber (12) is incorporated into the side wall (3). The base (2) includes a water reservoir, and a water distribution manifold is formed in the gap between a removable non-porous element (18) and a channel formed in the bottom (10) of the planting space. Thermal expansion of air within the air chamber (12) causes water to flow through the manifold and into the planting space. Cooling of the air chamber (12) causes water to return from the manifold, which is vented to atmosphere via a vent pipe (22). Excess water may drain from the planting space (8) into the manifold without being subjected to a pressure differential which would cause an increased risk of blockages.

Description

PLANTER

TECHNICAL FIELD OF THE INVENTION

This invention relates to planters, i.e. containers in which plants are grown.

BACKGROUND

Planters containing large plants, or which are densely planted, may quickly dry out, particularly under hot conditions, and even daily watering may not be sufficient to sustain the plants.

It is known that the expansion of air within an air space can be used to pump water out of a reservoir in order to irrigate plants which are grown in a pot or other small container. Various systems of this kind are disclosed in WO 01/01759 A1. However, whilst such watering systems are adequate for small plant containers there is a considerable problem with adequately irrigating a larger plant container without risk of over- saturating the growing medium. An excess of water can quickly lead to fungal diseases which may cause plants to rot and die. On the other hand, attempts to draw water out of the growing medium may result in blockage of the system and irrigation failure. The present invention seeks to provide a new and inventive form of planter which incorporates an irrigation system which is capable of delivering the required amount of water over a long period without risk of saturation or irrigation failure.

SUMMARY OF THE INVENTION

The present invention provides a planter having a base which is surrounded by an upstanding side wall to define a planting space, the side wall incorporating a gas tight air chamber which is subject to temperature variations in use, and the base including a water reservoir and a water distribution manifold arranged to receive water from the reservoir and which communicates with the planting space, an air passage connecting the air chamber to the water reservoir such that thermal expansion of air within the air chamber causes water to be supplied to the planting space via the manifold, and in which the manifold is provided with a vent passage which travels from the manifold to an opening located adjacent to or above an upper region of the side wall.

The manifold allows the water to be distributed to the planting space when expansion of air occurs within the air chamber. On the other hand, when the air pressure falls under cooler conditions the vent passage allows excess water to drain into the manifold and return to the reservoir without subjecting the growing medium to a pressure differential.

BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings:

Figure 1 is a general view, partly shown in transparent outline, of a planter in accordance with the invention;

Figure 2 is a longitudinal sectional through the planter;

Figure 3 is a transverse cross section through part of the planter;

Figure 4 is a more detailed longitudinal section through one end of the planter; and

Figure 5 is a similar view to Figure 4, but showing a modification to a detail of the planter.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring firstly to Fig.s 1 and 2, the planter 1 may be formed of glass fibre reinforced resin, metal sheet, terra cotta, glass, or moulded of thermoplastic material such as polypropylene, for example. The planter is in the form of a trough having a rectangular base 2 which is surrounded by a continuous upstanding side wall 3, including longitudinal walls 4 and 5 and end walls 6 and 7 which, together with the base 2, define an upwardly open planting space 8. The base 2 is of hollow construction, forming a sealed water reservoir 9 bounded by a platform 10 which also forms the bottom wall of the planting space 8. The upper margin of the side wall 3 incorporates a continuous duct, of rectangular cross section, which extends around the periphery of the planter to form a gas tight air chamber 12. It is important that the walls of both the air chamber 12 and the water reservoir 9 are substantially inflexible, and they may incorporate strengthening ribs or metal reinforcements if necessary. The interior of the air chamber 12 is connected to the interior of the water reservoir 9 by an air passage 13. Although the air passage could lie at least partially outside the side wall 3 it is preferably concealed within the planting space 8, passing sealingly through the platform 10 and the wall of the air chamber 12. Preferably, as shown in Fig. 2, one end 14 of the air passage 13 lies within an upper region of the air chamber 12, and the opposite end 15 preferably lies within an upper region of the water reservoir 9.

The platform 10 incorporates one or more removable elements 18, only one being shown in the present drawings. Referring to the detailed sectional view in Fig. 3, the upper surface of the platform 10 is formed with a longitudinal channel 19 which receives the element 18 as a close but non-sealing fit. If necessary, the bottom of the channel 19, and/or the opposing surface of the element 18, may be provided with water channels to assist water distribution. If two or more elements 18 are provided they may be located side-by-side in a single channel, or received in separate channels. Element 18 is formed of a strong but lightweight non-porous material such as resin reinforced with glass fibre, recycled thermoplastics, or the like. At least one water feed tube 20 is provided to conduct water from a lower region of the water reservoir 9, being sealingly inserted through the platform 10 to communicate with the bottom of the channel 19. The space formed between the element 18 and the channel 19 forms a water distribution manifold 21 which communicates with the planting space around the margins of the removable element 18. The platform 10 may be covered by a layer of porous matting 32 which overlies the element 18.

A vent pipe 22 is provided adjacent to one end of the planter (see Fig. 1 also). The vent pipe is preferably located within the planting space, having an upper opening 23 located proximate the upper margin of the side wall 3. The lower end of the vent pipe is inserted into the element 18 (or the platform 10) to communicate with the manifold space 21.

Referring to Fig. 4, a filler pipe 26 is also provided, leading from the interior of the water reservoir 9 to a position proximate the upper margin of the side wall 3. Again, the filler pipe is preferably located within the planting space, although it could lie at least partly outside the side wall 3. The filler pipe can be used to fill the reservoir 9 with water. The reservoir can be completely filled up to the top of the filler pipe, or it may be partially filled provided sufficient water is added to at least cover the lower end of feed tube 20. The filling level may be monitored by means of a transparent vertical window 27 in the wall of the water reservoir (Fig. 1). The upper end of the filler pipe 26 is provided with a removable filler cap 28 which sealingly closes the filler pipe when filling is complete.

It will also be noted that the air chamber 12 is provided with a top opening formed by a neck 29 which is normally sealed by a closure 30. The function of this opening will be described below.

The planter may be installed on a balcony or in any other location where temperature cycling will occur. The planter is filled with a growing medium 33, such as a proprietary plant compost, which is placed on the matting 32 so that the growing medium cannot enter the distribution channels of manifold 21. One or more plants 34 can be planted into the compost, as desired. The narrow slot-shaped openings of the distribution manifold 19 reduce the risk of plant roots penetrating the manifold as the plants grow.

When sunlight falls on the air chamber 12 the temperature of air in the chamber will rise resulting in a rise in air pressure within the chamber. This increased pressure is transmitted to the water reservoir 9 through the air passage 13, driving water up the feed tubes 20 and through the distribution manifold 21 to irrigate the compost in the planting space 8.

Some of the water within the planting space 8 will be lost by evaporation through the compost or absorbed by the plants 34. However, at night, the air chamber 12 will cool down resulting in a significant drop in pressure within the air chamber. When this occurs the resulting atmospheric air pressure acting through the vent pipe 22 causes water to be purged from the manifold 21 back into the water reservoir 9. Any excess of water within the growing medium 33 will drain into the manifold under gravity to return into the reservoir 9. It is important to note that this is achieved without subjecting the growing medium to any significant pressure differential. The water which has been lost by evaporation or used by the plants is replaced by bubbles of air which are drawn into the reservoir through the vent pipe 22.

In normal use a water reservoir with a capacity of say 30 litres will tend to use about 1 litre of water per day. The reservoir will therefore only require re-filling at intervals of about one month. During periods when automatic watering is not required, for example during the winter months, the filler cap 28 can simply be removed or loosened to admit atmospheric air pressure to reach the water reservoir. It will therefore be appreciated from the above description that the arrangement of the manifold 21 and vent pipe 22 ensures that unused water is conserved to prevent unnecessary water loss and significantly reduces the risk of saturation of the compost. This is achieved with a low risk of blockage which is sustained over a long period of use.

In locations which are subject to large swings of temperature the volume of water entering the planting space will be greater than under conditions of smaller temperature variation. The present planter allows the volume of water which is expelled to be controlled by varying the volume of air within the air chamber. This is conveniently achieved by partially filling the air chamber with water, sand or other flowable material through the neck 28, as indicated by the level line A in Fig. 4. If the air volume is reduced the amount of expansion is also reduced for a given change in temperature, resulting in a smaller volume of water entering the planting space. The water level may be monitored by means of a transparent vertical window 35 in the wall of the air chamber (Fig. 1) or by using a calibrated dip stick.

In order to monitor the amount of water within the reservoir 9 it is possible to avoid the additional complication of incorporating a transparent window, as shown in Fig. 5. The filler pipe 26 is replaced by a shorter external filler neck 26.1 which is again sealably closed by a cap 28. The neck 26.1 is upwardly inclined to facilitate the insertion of a dip stick into the water reservoir 9 to check the water level. It will be noted that when the planter is in use, the level of the filler neck 26.1 determines the maximum water level within the reservoir 9. An additional advantage of this arrangement is that during periods of very heavy rainfall when the reservoir may become full, the filler can be removed to allow excess water to drain from the reservoir. The filler neck can also be used to completely drain the reservoir 9 if the planter is tilted, e.g. for storage or transportation.

At the end of a growing period the growing medium will generally be replaced, at which time the elements 18 can be removed and the manifold 19 cleaned.

The air chamber could be provided with an electrical heating element operated by a timer for use as a backup system under conditions which are likely to produce inadequate temperature cycling to ensure sufficient irrigation.

It will be appreciated that the features disclosed herein may be present in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any inventive combination of the features disclosed herein.

Claims

1. A planter having a base (2) which is surrounded by an upstanding side wall (4-7) to define a planting space (8), the side wall incorporating a gas tight air chamber (12) which is subject to temperature variations in use, and the base including a water reservoir (9) and a water distribution manifold (18, 19) arranged to receive water from the reservoir and which communicates with the planting space, an air passage (13) connecting the air chamber to the water reservoir such that thermal expansion of air within the air chamber causes water to be supplied to the planting space via the manifold, and in which the manifold is provided with a vent passage (22) which travels from the manifold to an opening (23) located adjacent to or above an upper region of the side wall.

2. A planter according to Claim 1 in which the manifold is formed by a recess containing a removable element.

3. A planter according to Claim 2 in which the removable element is non-porous.

4. A planter according to Claim 1 in which the air chamber extends continuously around the upper region of the side wall.

5. A planter according to Claim 1 which includes provision for changing the volume of the air chamber.

6. A planter according to Claim 5 in which the air chamber has an opening provided with a sealing closure and through which a flowable substance can be introduced to reduce the volume of the air chamber.

7. A planter according to Claim 1 in which the air passage leads from an upper region of the air chamber.

8. A planter according to Claim 1 in which a filler passage extends from the water reservoir to a filler cap.

9. A planter according to Claim 8 in which the filler cap is located adjacent to the upper region of the side wall.

10. A planter according to Claim 8 In which the filler cap is located externally of the water reservoir adjacent to the top of the water reservoir.