GB2187221A - Greenhouse - Google Patents

Abstract

A greenhouse (particularly for domestic use) has a glazed roof 7 which is generally conical or frustoconical in overall shape. The roof 7 sits on a base 1 which may have a peripheral shelf (Fig. 6) for holding pot plants. A central pole may hold swivelling plant trays (Fig. 7). Access to the interior of the greenhouse is normally by reaching in from outside, and is obtained either by entirely removing the roof 7 from the base 1, or by removing one pane from the glazing frame. Ventilation may be controlled by angularly misaligning the superstructure 7 on the base 1 to form gaps 27, Fig. 14 between their respective corners. The shape of the greenhouse causes it to be highly efficient in terms of ground space, overall volume, and internal environmental factors such as heating and ventilation. <IMAGE>

Description

SPECIFICATION A greenhouse This invention relates to greenhouses.

In a conventional greenhouse, a portion of the internal space is allocated to access, and is therefore unavailableforgrowth of plants butstill requires heating and ventilation. Smallergreenhousesfor non-commercial use also tend to have surface-tovolume ratiosthatare much greaterthan the surface- to-volume ratios that occur in largercommercial greenhouses. High surface-to-volume ratio in a greenhouse results in a low thermal inertia, with rapid solar heating during daytime, and rapid cooling at night.

Thus conventional small greenhouses tend to be inefficient in their use of constructional materials, and to have excessive need for heating and ventilation.

In the remainderofthisspecification and in the appended Claims, the word "shed" is used in its traditional sense of referring to a sloping surface (or surfaces) which functions as a roof of a small outdoor structure to protectfrom falling rain.

According to the present invention there is provided a greenhouse having a shed which is generally conical orfrustoconical in overall shape, and at least partly composed of light-transmitting translucent ortrans- parent materials.

The shed may be a plane-sided pyramid with a lower end of polygonal section, for example, in the form of an octagonal pyramid which may be a regular pyramid (i.e. symmetrical).

The greenhouse may also include a base upon which the shed is mounted in use, the base being fixed in use to the ground orto a foundation and the shed being movable relative to the base, preferably by rotation and/or lifting. The base may be in the form of a hollow container, which may have a waterproof lining and may be partly or wholly filled (in use) with soil or hydroponic bedding material (gravel or artificial soil for hydroponic culture) to serve both to hold plants rooted therein, and to anchorthe base by reason ofthe weight of the filling.In the case where the lower end of the shed is polygonal in section and the upper edge of the base had a matching polygonal section upon which the shed can be mounted substantially without gaps, the shed may be rotatable relative to the base such that the vertices ofthe polygonal lower end ofthe shedandtheverticesofthepolygonal upperedgeof the base become angularly displaced and the sides of the respective polygons become misaligned to an extent that produces gaps between the shed and the base which allows ventilation ofthe greenhouse.

If theshed is afrustocone ora truncated pyramid, the greenhouse may be capped by an apex portion which may sit on or overthe upper end ofthe shed to function as an auxiliary shed. The apex portion is preferably vertically displaceable or entirely remov able to uncover a ventilation opening at the upper end ofthe main shed.

The shed may be mounted on a central spindle around which the shed can be rotated on a substantially vertical axis, and the shed may be suspended on the spindle by a spring, or have at least partof its weight offset by the spring, with vertical movement of the shed on the spindle being controlled byan over-centre toggle lever arrangement.

Access to the interior ofthe greenhouse may be gained by removing one or more light-transmitting panels from the shed, or by lifting the shed entirely away from items normally covered bytheshed. The peripheral dimensions ofthe greenhouse are desirably limited to an extent which allows a person standing outside the opened greenhouseto have manualaccesstomostorall parts ofthe space normally covered by the shed, either directly or through use of a hand-held horticultural implement.

The greenhouse may be vertically extended when desired by the insertion under the shed (i.e. between the shed and the base when a base component or assembly is employed) of a rightcircularor prismatic wall at least partially composed of light-transmitting translucent ortransparent materials.

The extension wall is generally cylindrical in overall shape, and may consist ofa number of rectangular transparent panels assembled in an outline matching thatofthe polygon formed by the lower end ofthe shed. The extension wall may carrythe weight ofthe raised shed. Thus the greenhouse may be vertically extended when required, for example to cope with plants that have grown to a height greaterthan could be accommodated by the shed alone.

An embodiment ofthe present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figs. 1 and 2 are respectively a side view and a plan view of a greenhouse ofthis invention, including a shed mounted on a base; Figs. 3 and 4 are respectively a side view and a plan view of a lower section ofthe base of the greenhouse of Fig. 1; Figs. 5 and 6 are respectively a side view and a plan view ofthe base of the greenhouse of Fig. 1; Fig. 7 is a side view of the base and central spindle assembly of the greenhouse of Fig. 1; Fig. 8 is a side view ofa detail ofthespindle of Fig. 7 showing a mounting fora plant tray; Fig. 9 is a plan viewofa planttrayforthe greenhouse of Fig. 1;; Fig. 10 is a side view ofa detail of the spindle of Fig. 7 showing a sub-assembly for use in raising the shed of the greenhouse; Fig. 11 is a side view of a detail ofthe interface between the base and the shed of the greenhouse of Fig.1; Fig. 12 (a) and (b) are side views ofpartofthe shed of the greenhouse of Fig. 1 illustrating the removal of a panel from the shed; Fig. 13 (a) and (b) are plan views ofthe greenhouse of Fig. 1 showing the shading of panels and rotation of the shed; Fig. 14 is a plan view ofthe greenhouse of Fig. 1 with the shed rotated on the base into misalignment with the base for ventilation oftheinteriorofthegreen- house; Fig. 15 is a side view ofthe greenhouse of Fig. 1 with an apex portion or top cone raised for ventilation;; Fig. 16 is a side view ofthe greenhouse of Fig. 1 with an extension section installed between the base and the shed; and Figs. 17, 18 and 19 are constructionai details of parts ofthegreenhouse of Fig. 1.

Referring nowto the drawings, the greenhouse of this embodimentofthe invention has an octagonal base 1 consisting of a lowersub-assembly2 in the form of a parallel-sided hoop which measures 1.36 metres across the flats and has a wall height of 16 centimetres. An upper sub-assembly 3 incorporates a shelf 4which is shaped to accommodate pot plants 5.

The outer horizontal top ofthis assembly is fitted with a soft plastic buffer/sealing strip 6 which provides an 'interface' between the base 1 and the shed ofthe greenhouse, the shed being in the form of a glazed superstructure 7. The lower end ofthe shed 7 lies within a hypothetical escribed circle of approximately 1.8 metres in diameter, which represents a desirable limit of peripheral dimensions on the basis of allowing a person standing outside the greenhouse to have manual access to most or all parts of the space normally covered by the shed 7.

The two octagonal sub-assemblies 2,3 forming the base are constructed from aluminium or uPVC extrusions having "Zed" profiles (Figs. 18 and 19). The extrusions are mitred to an angle of 67.5 degrees, and jointed on each angle by means of metal plates. The plates locate into guide channels, and are secured in place by studs orthrough-bolts.

Atubularsteel pole or mast 8 is anchored to the ground centrally within the base 1. The main purposes ofthe pole 8 are (a) to anchorthe entire structure to the ground and (b) to support the shed or glazed superstructure 7.

As well as performing the above functions, the pole 8 supports a number of trays 9 which are attached to the pole 8 in a helical formation. These trays 9 may be adjusted up and down the pole 8 in a vertical plane, or swivelled around the pole 8 in a horizontal plane, according to the placement requirementforgrowing plants.

The pole 8 has an approximate outside diameter of 45 millimetres. In service, it is accommodated within a foundation tube 10 of slightly larger diameter set down into the ground and backfilled with a concrete mix. Alternative anchorage can be provided by welding a shortened foundation tube to a flat steel plate, and in turn bolting the plate to a concrete or paving slabto form afoundation.

The pole 8 is locked into the foundation tube 10 by means of a removable steel pin 11 which is inserted at right angles through the two concentric tubes 8 and 10. This arrangement allows the pole 8 complete with an attached shed or glazed superstructure 7 to be removed for repairs or maintenance orfor relocation onto another base.

The swivelling trays9 affixed to the centre pole 8 are supported in the vertical plane by adjustable stops (Fig. 8). The stops consist of runner "0" rings 12, housed within tapered spun rings 13. When loaded, the trays 9 apply a downward pressure which traps and jams the "0" rings 12, thus lockingthe stop to the pole 8 at any pre-selected height on the pole 8.

Thetrays9 are fan-shaped in plan (Fig. 9) and are constructed from welded steel mesh, and coated with an epoxy resin. Raised edges tnot shown) prevent plants from sliding off the trays 9. The trays 9 provide adequate mechanical support and drainage to the plants, while unoccupied areas present minimum resistance to heat, light and ventilation.

At the top ofthe pole 8 there is a sub-assembly (Fig.

10) consisting of a steel coil-spring 14, a thrust bearing 15 and an over-centre fastener 16.

This sub-assemblyprovidesthe interface between the pole 8 and the shed or glazed superstructure7. Its function allows the superstructure 7 to beturned around a vertical axis to any angle, and to be locked at any desired angle with respectto the base 1. The steel coil spring 14is designed to bearthefull weight of the superstructure 7 (50 kilogrammes) and to require a further 15 kilogrammes of downward thrust to be applied in orderto achieve 40 millimetres of compression.

The thrust bearing 15 is located overthecoil-spring 14 and supports the hub 17 ofthe superstructure 7.

The bearing 15 allows free rotation ofthe superstruc- ture 7 in a clockwise or anti-clockwise direction around avertical axis.

The over-centre fastener 16, is anchored by its upper leg 1 8Ato the hub 17 of the superstructure 7; thus it rotates with the superstructure 7. A lower leg 1 8B of the fastener 16 is anchored to a simple bush bearing 19 which slips round in light contact with the pole 8 during rotational movement. When the fastener 16 is operated, the bush 19 bears into contactwith a fixed stop 20 anchored to the pole 8, and a compressive force is hereby applied to the coil-spring 14via the hub 17, such that the superstructure 7 descends around 40 millimetres before being locked into tight peripheral contactwith the base 1.

The superstructure 7 consists ofeighttriangular or trapzoidal panes oftransparent glass 21 which form a truncated regular octagonal pyramid. The panes 21 are assembled within a simple fra mework of uprig ht glazing bars 22 (Fig. 1 ) anchored at the top to a hub at the bottom to cross members 23 (Figs. 11,19) which form an octagon of equal dimensions to those of the base upper sub-assembly 3.

All ofthe glass panes 21 are sealed into the glazing bars 22 using extruded PVC or neoprene gasket ofthe type used in secondary double glazing systems.

Glazing springs are not used, and replacement of panes is effected by removing uptothree glazing bars and panes in orderto getto the broken pane.

Quick-release fasteners are used on all glazing-barsto facilitate this action.

Ofthe eight panes 21 ofglass one 21A is removable (Fig. 12). The lower edge of this pane 21 A is cut 40 millimetresshorterthanfortheothersevenfixed panes 21. This produces a gap 23 into which the pane 21 A can be lowered, and by virture of its 'wedge' shape it then detaches from the frame and can be withdrawn. Access is thus gained into the growing area.

The shed or glazed superstructure7 has an apex portion or top cone 24 which is moulded in plastics or glass-fibre. It is adjustable in a vertical direction 24A (Fig. 15) to allowvariableventilation rates through the greenhouse.

Where extra height is required over an existing base 1,the glazed superstructure7 can be mounted on an extended height pole and a parallel sided extension 25 can then be bolted into place (Fig. 17). This morethan doubles the growing area, and provides ample accommodation fortallercrops such astomatoes.

The rotation of the superstructure 7 allows all internal growing areas to be accessed through a single entry port 21A. The same action allows darkened or opaque glass panels 21 B (Fig. 13) to be fitted where required and for these to be rotated to provide variable shading to plants. When the shed 7 is rotationally aligned with the base 1 and their octagonal perimeters are locked in alignment, the internal environment of the greenhouse is effectively sealed off from the weather. However, in warmer weather the shed 7 may be rotated on the base 1 and then locked in misalignment (Fig. 14) to produce eightventilation slots 27 at the interface, which can be adjusted to provide a greateror lesser rate of air-flowthroughthe green- house structure, as desired.

The greenhouse ofthis embodiment ofthe invention has several substantial advantages over conven- tional designs. Although very compact in overall dimensions it provides a very large space which can be used exclusively for growing plants. The green- house is not designed for entry by humans, as its shape and rotational superstructure allows easy access to all parts ofthe interior by a person standing outside the greenhouse.

Glazed cones such as the shed 7 retain heat more effectively than the rectilinear box structures of conventional greenhouses since a conical structure has no large upper spaces into which the heat can rise, and the upper spaces of a cone have relatively small surface area for conduction losses, in comparison to conventional rectilinear greenhouse structures. Further, cones are very efficient in promoting convection of air, such that plants in the greenhouse ofthe invention are subjectedto ventilating airflowwhile heat is effectively retained.

The modular construction ofthe greenhouse ofthis embodimentallowsseedstobepropagated, har dened off and grown to maturitywith the shed or glazed superstructure 7 in place or easily removed depending on the prevailing weather conditions.

The base 1 may befilledwith natural orartificial growing medium to provide a raised bed which is easilyaccessibleto people, including disabled persons. The raised base 1 presents a barrier two slugs and crawling insects. The raised bed also constitutes a heat store by absorbing warmth from the sun during the day and releasing it into the interior of the greenhouse during the night.

Ventilation is widely variable by optional removal of the pane 24A, by selective variation of the rotational alignment or misalignment ofthe shed or glazed superstructure 7 on top ofthe base 1 as in Fig. 15, and by raising or lowering the top cone 24.

The illustrated greenhouse design is also stable in high winds.

Modifications and improvements may be incorporated without departing from the scope ofthe invention.

Claims (18)

1. A greenhouse having a shed (as hereinbefore defined) which is generally conical orfrustoconical in overall shape, and at least partly composed of light-transmitting translucent ortransparent materials.

2. A greenhouse as claimed in Claim 1, in which the shed is a plane-sided pyramid with a lower end of polygonal section.

3. A g reenhouse as claimed in Claim 1 or Claim 2, including a base upon which the shed is mounted in use.

4. Agreenhouse as claimed in Claim 3,wherein the shed is movable upon the base by rotation and/or by lifting.

5. A greenhouse as claimed in Claim 3 or Claim 4, wherein the base is in the form of a hollow container.

6. A greenhouse as claimed in Claim 3 or 4 or Claim 5, wherein the lower end ofthe shed is polygonal in section and the upper edge ofthe base has a matching polygonal section upon which the shed can be mounted substantiallywithout gaps, and wherein the shed is rotatable relative to the base such that the vertices of the polygonal lower end ofthe shed become angularly displaced and the sides ofthe respective polygons become misaligned to an extent that produces gaps between the shed and the base which allows ventilation ofthegreenhouse.

7. Agreenhouse as claimed in any preceding Claim wherein the shed is frustocone or a truncated pyramid, and the greenhouse is capped byan apex portion which sits on or over the upper end of the shed to function as an auxiliarvshed.

8. A greenhouse as claimed in Claim 7, wherein the apex portion is vertically displaceable or entirely removable to uncover a ventilation opening at the upper end ofthe main shed.

9. A greenhouse as claimed in any preceding Claim wherein the shed is mounted on a central spindle around which the shed is rotatable on a substantially vertical axis.

10. A greenhouse as claimed in Claim 9, wherein the shed is suspended on the spindle by a spring or has at least part of its weight offset by the spring.

11. A greenhouse as claimed in Clain 10 wherein vertical movement ofthe shed on the spindle is controlled by an over-centre toggle lever arrangement.

12. A greenhouse as claimed in any preceding Claim, wherein the shed is glazed with a plurality of panels of the light-transmitting material.

13. A greenhouse as claimed in Claim 12 wherein one or more of said panels are removable from the shed to allow access to the interior of the greenhouse.

14. A greenhouse as claimed in Claim 12 or Claim 13 wherein at least one but not all of said panels are substantially opaque whereby the shed may be rotated to bring the opaque panel or panels between the sun and the interior of the greenhouse for selective shading ofthe plants in the greenhouse.

15. A greenhouse as claimed in any preceding Claim wherein the peripheral dimensions of the greenhouse are limited to an extent which allows a person standing outside the opened greenhouse to have manual accessto mostorall ofthe parts ofthe space normally covered by the shed.

16. A greenhouse as claimed in Claim 15 wherein thelowerend oftheshed lieswithin a hypothetical escribed circle of approximately 1.8 metres india- meter.

17. Agreenhouse as claimed in any preceding Claim, in combination with a ri3htcircularor prismatic wall at least partially composed of light-transmitting translucent ortransparent materials, said wall being inserted under the shed to extend the height of the greenhouse.

18. A greenhouse substantially as hereinbefore described with reference to the accompanying drawings.