GB2364229A - Propagator - Google Patents

Abstract

The propagator comprises an enclosure (10,11,12) having heat absorbent material (23) (eg. polystyrene) arranged to be heated, in use, and to transmit heat to a growing medium disposed, in use, in said enclosure (10,11,12). The enclosure preferably comprises a lowermost chamber (10), an upper chamber (11) and an uppermost chamber (12). A heating means 29, which may be paraffin, oil or electric heater may be placed in the lower chamber. The propagator may also include an artificial light source and may have electronically dosable ventilation openings controlled by a thermostatic control means comprising a temperature sensor.

Description

2364229 PROPAGATION ASSEMBLY/PROPAGATOR This invention relates to a

propagation assembly/propagator for germinating seeds and/or raising seedlings.

Known propagators for germinating seeds are conventionally heated by an electrical heater or a paraffin heater. Electrical heating is relatively expensive and an electrical supply to the potting shed or greenhouse where the propagator is situated is required. Whilst a paraffin heater is more convenient, there still remains the problem of hot or warm spots being created in the propagator, i.e. the heat is not evenly distributed.

An object of the invention is to provide a propagation assembly/propagator in an effective form.

According to the invention a propagation assembly/propagator comprises an enclosure having heat absorbent material arranged to be heated, in use, and to transmit heat to a growing medium disposed, in use, in said enclosure.

Preferably the material divides a lowermost chamber, containing heating means, in use, from an upper chamber defining said enclosure. Desirably the material is carried on a slatted shelf forming a base of the upper chamber, and conveniently the material is polystyrene. Advantageously the upper chamber has a sliding, front door, which is preferably transparent. In a preferred embodiment an uppermost chamber is arranged above the upper chamber for growing on seedlings produced by the germination process in the upper chamber. More preferably the division between the upper chamber and the uppermost chamber is provided by further heat absorbent material. Most preferably said further heat absorbent material is less thick than the heat absorbent material between the lowermost and upper chambers, and in one embodiment said uppermost chamber has a hinged transparent lid or cover.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a front view of a propagation assembly/propagator of the invention, Figure 2 is a top plan view of the propagation assembly/propagator of Figure 1, and Figure 3 is an enlarged, interior end view of the propagation assembly/propagator of Figures 1 and 2.

The embodiment of a propagation assembly/propagator of the invention which is shown in the drawings is relatively large-scale, being typically 365 cm in length, 36 cm in width and 140 cm high. Whilst it is envisaged that the assembly could be sold in a kit form, it is also envisaged that it could advantageously be incorporated into a potting shed or greenhouse when the shed or greenhouse is originally constructed. It will, however, be appreciated that the propagation assembly /propagator could be produced in a much smaller form so that it is possibly portable.

In the embodiment shown in the drawings, it can be seen that the propagation assembly/propagator, hereinafter referred to solely as a propagation assembly, comprises a structure having lower, middle and upper enclosures or chambers 10, 11, 12 respectively arranged one above the other, with each chamber extending uninterruptedly along the length of the propagation assembly.

The propagation assembly, which is of rectangular shape, has its rear formed by a single flat sheet 13 of transparent material, such as Perspex. The base 14 of the assembly is formed of aluminium, having four holes 15 therein, each hole being equally spaced between the front and rear of the assembly. The holes are spaced along the length of the aluminium base, with each end hole being spaced equally from its next inboard hole, but with said inboard holes being spaced apart to a greater degree.

As shown in Figure 3, the aluminium. base is continued a short way upwardly at the front of the assembly to provide an elongate upstand 16 extending along the whole of the length of the front of the assembly at the bottom thereof. The opposite ends of the assembly can be closed in any convenient manner, but preferably each opposite end is formed merely by a one-piece flat panel. The panel can be of any suitable material, for example Perspex.

Interiorly, the assembly is, as mentioned, divided into three chambers 10, 11 and 12. The top of the lower chamber, which also forms the base of the middle chamber 11, is made up of five parallel, laterally spaced apart bars 17, for example of hollow extruded aluminium. section, the bars 17 extending between the respective panels at the opposite ends of the assembly, and being secured thereto to form a fixed shelf. Typically the lateral spacing between each pair of bars is of the order of 3.8 cm. Similarly the top of the middle chamber and the base of the upper chamber is formed by an identical set of five parallel spaced apart bars 18, which again extend throughout the length of the assembly, being fixed at the opposite end panels thereof, to form a shelf. Again these bars are typically of hollow section and made of extruded aluminium, with the same space therebetween.

Attached to the front bar of the two shelves described, are upper and lower elongate aluminium bars 19, 20 respectively, which bars extend in the same manner as the upstand 16, and parallel thereto, along the whole of the front face of the assembly, the bars 19 and 20 being in the same vertical plane as the upstand 16. These front bars are to accommodate sliding doors for the lower and middle chambers, and to this end whilst the bar 19 is downwardly grooved, and the upstand 16 upwardly grooved, the bar 20 is grooved both in its upper and lower edge faces. Accordingly, as shown in Figures I and 3, there are three rectangular Perspex sliding doors 21 at the front of the middle chamber 11, these running in the respective lower and upper grooves of the bars 19 and 20. Figure I shows the three doors in their closed positions so that the middle chamber is isolated from the exterior at the front of the assembly. Similarly three rectangular sliding doors 22 of aluminium. are provided at the front of the lower chamber 12, each door sliding by way of the respective upper and lower grooves in the aluminium. upstand 16 and bar 20. Again, Figure 1 shows these aluminium sliding doors closed so as to isolate the lower chamber from the exterior at the front of the assembly, even though air can enter this lower chamber through the holes 15 previously described.

The shelf formed by the bars 17 carries thereon an elongated rectangular layer/strip 23 of heat absorbent material, for example polystyrene. The strip extends across the whole width of the interior of the assembly and also extends along the whole length of the interior thereof so as to form a division between the lower and middle chambers. Typically this strip on the lower shelf is 38 mm thick. A similar heat absorbent layer/strip 24, again typically of polystyrene, is received on the upper bars 18, this strip again extending across the whole of the internal width and along the whole of the internal length of the assembly. In this case, however, the strip thickness is less than the thickness of the strip 23, being, for example, typically 19 mm.

Finally with regard to the structure of the assembly, there is a cover 25, preferably of Perspex, forming top and front surfaces respectively of the assembly. The cover thus has a top flat part 26, which is hinged along its rear longitudinal edge to the top longitudinal edge of the rear panel 13. The cover is completed by a front flat part 27 which is integral with the part 26 and at 90' thereto so as to lie parallel to the rear panel 13 and in a plane slightly outwardly of the plane containing the front surfaces of the upstand 16 and bars 19 and 20, as shown in Figure 3. The cover 25, together with the upper part of the rear panel 13 and the upper shelf thus defines the upper chamber 12. Finally it will be noted that the top flat part 26 of the cover 25 is formed with three adjustable ventilation holes 28 which, as will be described, can be open or closed to vary the temperature in the upper chamber 12.

As shown in Figures I and 3, it is intended that the assembly is heated by three paraffin heaters 29 disposed in chamber 10, the heaters being equispaced apart along the chamber so that, in effect, if each sliding door 22 is considered to represent a sub-division of the continuous lower chamber 10, there is a heater positioned centrally in each sub-divided chamber. Typically the paraffin heater can be of a capacity to provide heat for approximately ten days. However, any other suitable heating means could be provided, for example oil or electrical heaters. If required, these could be fixed in position with the aluminium base, or alternatively the heating means can be removable and may or may not form part of the assembly initially installed in a shed or greenhouse, and similarly may or may not form part of the kit for constructing the propagation assembly.

Although discrete, individual heat sources are provided in the lower chamber 10, the provision of the heat absorbent material above these heat sources overcomes the prior art problem of hot/wann spots being produced in the area where the seeds are germinating. As will be explained, in use, below, the presence of the heat absorbing material 23 means that the heat from the paraffin heaters rises within the lower chamber 10 and passes through the spaces between the bars 17 thereby heating the polystyrene strip 23, the rise in temperature of the strip 23 being substantially evenly distributed throughout the whole of its length and width so as to eliminate said aforementioned hot spots. Thus there is an even transfer of heat to the strip 23, and, as will be described, a similar even transfer of heat therefrom to the soil in seed trays (not shown) placed, in use, on said shelf.

Accordingly, in use, an appropriate number of seed trays, for example 14 standard sized trays, are placed in the middle chamber 11 on the shelf formed by the bars 17 and the polystyrene strip 23 thereon. Each seed tray contains a suitable growing medium in which are the seeds to be germinated. Once the trays have been placed as required in the chamber 11, the sliding doors 21 are moved to the closed position shown in Figure I and the propagation assembly is put into use by actuating the paraffin heaters 29. As described, the heat rises through the lower chamber 10 to heat the strip 23, the heat in this strip being transferred to the base of the seed trays in contact therewith, and thence to the growing medium, for example soil and compost, which is warmed, thereby encouraging germination of the seeds in said seed trays. If required, it would be possible to make the sliding doors, and/or the rear of the middle chamber I I less transparent, this depending upon the nature/type of the seeds to be germinated in the chamber 11. Typically the temperature in this chamber will be an even 551 - 65'C, but this can be varied as required by varying the output of the paraffin heaters, and perhaps operating them in sequence. As mentioned, the distribution of heat to the seed trays by the heat absorbent strip 23 is such that there is an even warming of the growing medium in all of the seed trays so that a controlled regulated environment is produced in the second chamber 11.

The upper chamber 12, which could be omitted if not required, is intended for the growing-on of the seedlings produced by germination in the middle chamber 11. Such young plants in their infancy are particularly vulnerable and a controlled growing environment is again very important thereto, so that this chamber 12 can be said to act as an intensive care chamber, the temperature therein normally being lower than in the chamber 11, for example below 501C, although this can be varied, not only by way of the paraffm heaters 29, but also by opening or closing one or more of the ventilators 28. For example, with all three ventilators closed, it is possible to bring the temperature in the chamber 12 up to 651C. Moreover, with the cover being wholly of Perspex, as described, the plants are subject to daylight, although again this could be varied by the use of material other than Perspex for the cover. It will be appreciated that heat from the middle chamber 11 will rise through the gaps between the upper bars 18 so as to heat the polystyrene strip 24. However, whilst the amount of heat reaching this strip will be less than that reaching the strip 23 which is nearer the heaters, the heat transfer at the strip 24 will be quicker given that it is, for example, only half the thickness of the strip 23. Accordingly, by choice of a suitable thickness of strip 24, the temperature in the upper chamber 12 can be controlled as required. It will be appreciated that it is of course intended that seeds germinated in the second chamber are removed therefrom and placed into the upper chamber 12 at an appropriate time, with the middle chamber then being filled again with seeds for germination. However, as described, the middle chamber could be used without the upper chamber being employed, or vice versa.

Although one embodiment of the invention has been described, it will be appreciated that many variations are possible. Instead of polystyrene, any other suitable heat absorbent material could be provided, and in particular the material could be coated or otherwise arranged to be fire resistant. If required, each of the sliding doors could be provided with a finger hole or the like for ease of opening and closing, and instead of the cover being hinged as shown, it could instead be of a form which can be lifted off and thereafter replaced onto the upper shelf, i.e. the removable cover could be formed of front and rear surfaces together with its flat top. Similarly, of course, each door could be hinged rather than sliding. Ventilation openings could be provided, like the holes 28, at other positions of the assembly, and the holes 15 for drawing combustion air to the heaters 29 could be varied as required, and could of course be omitted if electrical heating means were provided.

In a first improvement to the embodiment described and illustrated, it would be possible to arrange for automatic opening and closing of the ventilation holes 28 by thermostatic control, using suitable temperature sensing means in the upper chamber 12, with suitable electronic control means, thereby ensuring an appropriate controlled temperature for the growing-on process. Moreover, in a further improvement, it is envisaged that in the middle and/or upper chambers photoelectric cells could be provided to provide artificial light during at least some of the hours of darkness, thereby, in effect, decreasing the hours of darkness and thus increasing the growing time. In this way seeds can be germinated and/or seedlings grown-on, for example, during the winter, thereby to provide plants effectively 'out of season'.

Claims (19)

1. A propagation assembly comprising an enclosure having heat absorbent material arranged to be heated, in use, and to transmit heat to a growing medium disposed, in use, in said enclosure.

2. A propagation assembly as claimed in claim 1, wherein said heat absorbent material is polystyrene.

3. A propagation assembly as claimed in claim 1 or claim 2, wherein said heat absorbent material is inherently fire resistant, or treated so as to be fire resistant.

4. A propagation assembly as claimed in any preceding claim, additionally comprising said heating means.

5. A propagation assembly as claimed in claim 4, wherein said heating means comprises at least one of a paraffin heater, or an oil heater or an electric heater.

6. A propagation assembly as claimed in any preceding claim, wherein said enclosure comprises an upper chamber and a lowermost chamber, said heat absorbent material dividing said lowermost and upper chambers, said lowermost chamber being adapted to receive heating means in use.

7. A propagation assembly as claimed in claim 6, additionally comprising a slatted shelf, said shelf forming a base of the upper chamber and said heat absorbent material being carried on said shelf.

8. A propagation assembly as claimed in claim 6 or claim 7, wherein the upper chamber has a sliding, front door, which is preferably transparent.

9. A propagation assembly as claimed in any one of claims 6 to 8, wherein an uppermost chamber is provided above the upper chamber.

10. A propagation assembly as claimed in claim 9, wherein the upper chamber and the uppermost chamber are divided by further heat absorbent material.

11. A propagation assembly as claimed in claim 10, wherein said further heat absorbent material is less thick than the heat absorbent material between the lowermost and upper chambers.

12. A propagation assembly as claimed in any one of claims 9 to 11, wherein said uppermost chamber has a hinged transparent lid or cover.

13. A propagation assembly as claimed in any preceding claim additionally comprising an artificial light source.

14. A propagation assembly as claimed in any preceding claim additionally comprising closable ventilation openings.

15. A propagation assembly as claimed in claim 14, wherein temperature sensing means and electronic control means are provided, said ventilation openings being openable and closable by said electronic control means under thermostatic control.

16. A propagation assembly as claimed in claim 14 or claim 15, when appended to any one of claims 9 to 12, wherein said ventilation openings are provided in said uppermost chamber.

17. A propagation assembly as claimed in any preceding claim which is adapted to be portable.

18. A propagation assembly as hereiribefore described with reference to any one of figures 1 to 3.

19. A kit of parts for a propagation assembly as claimed in any preceding claim.