WO2014113838A1

WO2014113838A1 - An improved lighting assembly for intensive plant cultivation

Info

Publication number: WO2014113838A1
Application number: PCT/AU2014/000031
Authority: WO
Inventors: Michael John Leslie
Original assignee: Vertical Farm Systems Pty Ltd
Priority date: 2013-01-22
Filing date: 2014-01-21
Publication date: 2014-07-31

Abstract

A plant cultivation installation includes a number of plant growth solution conduits disposed between opposed support members. Light assemblies are located between the opposed support members for illuminating plants growing from the plant growth solution. Each light assembly includes an elongate and heat conductive support structure. One or more elongate panel assemblies, each having an electrical circuit and LED light source are coupled to each support structure. Heat is dissipated from the panels to the support structure during use. Each panel includes an electrical circuit having at least one electrical connector disposed at one of its ends that is interconnected with an adjacent panel. Ends of the light assemblies are received into corresponding engagement formations of the opposed support members to thereby provide mechanical and electrical coupling to the light assemblies. In the event of an LED failing the associated light assembly can be quickly uninstalled, the affected panel replaced with a functional panel and the restored light assembly reinstalled.

Description

AN IMPROVED LIGHTING ASSEMBLY FOR INTENSIVE PLANT

CULTIVATION

TECHNICAL FIELD

[01 ] The present invention is directed to a method and apparatus for providing light in situations where high light densities are required such as in intensive plant cultivation installations.

BACKGROUND

[02] The present invention will be described in the context of its use for lighting in intensive plant cultivation contexts. For example, in hydroponic, and bioponic plant cultivation it is often the case that plants are grown indoors under artificial lights.

[03] Typically light is provided by fluorescent lighting however more recently there has been a trend towards using light emitting diodes (LEDs). LEDs include a semiconductor junction and so work best when they are kept cool. Indeed, the photon flux produced by an LED decreases as the semiconductor junction becomes hot. Apart from improving the light emission-to-power consumption ratio, reducing the operating temperature of the semiconductor junction increases the device's lifetime.

[04] Given that numerous LEDs are required in a large plant cultivation installation it is desirable to prevent their temperature rising too high in order to limit power consumption, and so operating cost for a desired light intensity.

[05] In addition to the above mentioned considerations, it is also important that the LEDs, which are installed relatively close to the growing plants, are not allowed to become so hot that they might harm the plants. [06] Accordingly, it will be realized that on one hand it is desirable to install the LEDs close to the growing plants whereas on the other hand it would be detrimental to the plants if the LEDs reached a temperature that might be harmful to the plants.

[07] As well as providing an LED fitting wherein the temperature of the LEDs is controlled, it is also important that it be simple to install and easily maintainable. For example, if one or more LEDs, or the circuit supplying the LEDs fails, then it is important that a maintenance person can quickly replace the failed LED fitting. It is also desirable that the faulty LED fitting can be quickly repaired.

[08] In the past there have been a number of approaches to providing an LED fitting or installation that attempts to meet one or more of the various requirements discussed above.

[09] For example, in US Patent Publication No. 20120192486 by Shanahan et al., there is discussed an LED light bar which comprises an extruded aluminum member formed with longitudinal heat sink fins. An array of discreet LEDs is disposed along the length of the light bar between the fins. The light bar is suspended from a suitable structural member by set screws which attach to the structural member and to the light bar respectively. Although it is possible to couple the light bar to the structural member in this way, the patent specification is silent as to the manner of electrical connection and presumably the electrical connection of the LEDs to a power source must be made in a subsequent separate operation.

[10] It is an object of the present invention to provide an LED fitting which addresses one or more of the above described problems and is an improvement, or at least a useful alternative, to those LED installation systems of the prior art. [1 1] Any references herein to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge in Australia or any other jurisdiction.

SUMMARY OF THE INVENTION

[12] According to a first aspect of the present invention there is provided a light assembly comprising:

an elongate and heat conductive support structure;

a number (i.e. one or more) elongate panel assemblies coupled to said support structure for heat conduction thereto;

wherein each of said panels includes an electrical circuit having at least one electrical connector disposed at an end thereof and at least one LED.

[13] Preferably the light assembly includes at least two of the panel assemblies wherein adjacent panels are placed in electrical communication with each other by means of at least one said electrical connector of each panel.

[14] Preferably an outermost of the electrical connectors is located proximate an end of the stiffening member.

[15] Preferably the heat conductive support structure includes a metal extrusion including opposed engagement formations holding the one or more elongate panel assemblies.

[16] In a preferred embodiment of the invention the opposed engagement formations comprise longitudinal slots for receiving opposed edges of the panel assemblies.

[17] The one or more elongate panel assemblies preferably comprise a number of Metal Clad Printed Circuit Boards (MCPCBs). [18] In an alternative embodiment of the invention the one or more elongate panel assemblies comprise a number of printed circuit boards (PCBs) coupled to the support structure.

[19] The PCBs may be coupled to the support structure by means of a plate which is engaged by the metal extrusion. A layer of one or more pieces of heat transfer material may be located between the PCBs and the plate for enhancing heat transfer from the PCBs to the plate and thence to the metal extrusion.

[20] Preferably the member and/or the plate are formed with apertures therethrough to promote air circulation.

[21] According to a further aspect of the present invention there is provided a plant cultivation installation including a plurality of plant growth solution conduits disposed between opposed support members;

a number of the previously mentioned light assemblies disposed between the opposed support members;

wherein ends of the light assemblies are received into corresponding engagement formations of the opposed support members.

[22] Preferably the engagement formations include:

recesses or (openings or apertures) receiving the ends of the support structure of each said light assembly; and

an electrical connector mated with said outermost of the electrical connectors of the panel members whereby the light assembly is mechanically and electrically coupled to the support structure. [23] According to another aspect of the present invention there is provided a method for maintaining lighting in a plant cultivation installation comprising the steps of:

installing a plurality of the previously described light assemblies into the plant cultivation installation;

in response to detecting a failure of an LED of one of the light assemblies removing said light assembly from the plant cultivation installation; and

replacing a panel associated with the failed LED from said light assembly with a functional panel to thereby restore functionality to the light assembly; and

reinstalling said restored light assembly in the plant cultivation installation;

wherein the steps of installing and reinstalling include mechanically and electrically coupling each light assembly to a support structure of the plant cultivation installation in a single action.

BRIEF DESCRIPTION OF THE DRAWINGS

[24] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[25] Figure 1 depicts an intensive plant cultivation installation according to a preferred embodiment of one aspect of the present invention.

[26] Figure 2 is an exploded view of an underside of a light assembly according to a preferred embodiment of an aspect of the present invention. [27] Figure 2A is an assembled detail view of an end of the light assembly of Figure 2.

[28] Figure 3 is an end view of the light assembly of Figure 2.

[29] Figure 4 is a view of the underside of one end of a light assembly according to a second and less preferred embodiment of an aspect of the invention.

[30] Figure 5 is a further view of the light assembly of Figure 4, being a view of a portion between the ends of the assembly.

[31] Figure 5A is a further view of the light assembly of Figure 4, being a view of another end of the assembly.

[32] Figure 6 depicts three of the light assemblies disposed between two horizontal supports according to a further embodiment of the present invention.

[33] Figure 7 is a close up of a receptacle of one of the horizontal supports of Figure 6.

[34] Figure 8 is a partially cutaway side view of one end of the plant cultivation installation of Figure 1 illustrating the installation of a light assembly according to an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[35] Referring now to Figure 1 , there is depicted a plant cultivation installation 2 according to a preferred embodiment of an aspect of the present invention. The installation 2 includes a plurality of growth solution supply conduits 4 along which there are spaced plants 3 which derive their nutrition from a plant growth solution that is conveyed through the conduits 4. [36] Above each supply conduit 4 there is disposed an elongate LED light assembly 6, or as it might also be called a "light fitting", "light bar" or "light rail". The LED light assembly 6 spans between opposed support members in the form of pillars 8a, 8b, disposed at either end of the plant cultivator 2.

[37] Referring now to Figure 2, there is shown an underside and exploded view of a light assembly 6 being one of the light assemblies depicted in Figure 1.

[38] The light assembly 6 comprises an elongate and heat conductive stiffening member in the form of an extruded rail 10. The rail 10 is typically made of aluminum though other suitable materials (e.g. stainless steel) might also be used in other implementations. A longitudinal stiffening rib 21 is formed along the inside midline of the rail 10 to impart additional rigidity, toward each outer end of the rail 0 the outer edges 17 are cutaway to leave an insertion end portion 23 for insertion into a receptacle (an example of which will subsequently be discussed in relation to Figure 7) when installing the light assembly 6.

[39] Figure 2A is an assembled, detail view of the light assembly 6 in which the insertion end portion 23 can be clearly discerned.

[40] Referring again to Figure 2, a number, in the present instance three, elongate LED panels 12 (or as they are sometimes referred to herein simply "panels") are supported by the rail 0. As may be more readily observed from the end view of Figure 3, the rail 10 is formed with inwardly and upwardly facing slots 14 along opposed edges 17 of the rail 10 for receiving the outer edges of the LED panels. Due to the angling of the slots 14 the panels 12 are held reasonably firmly by the rail 10. While the panels 12 are held firmly, nevertheless they can be slid along the rail 10 with the application of manual force in order to remove them or insert them into the rail as desired. For example, in the event of an LED or associated circuitry of a panel failing the affected panel may be readily removed from the rail. [41] It will be seen from Figure 2 that along the borders of the rail 10 there are formed a plurality of apertures 16. Similarly, the panels 12 are also formed with apertures 18 therethrough. The apertures 16, 18 assist in allowing air to circulate and cool the rail 10 and the panels 12 in use.

[42] Each of the panels 12 includes an electrical circuit that has at least one LED 20 and also has electrical connectors 22 in addition to other electrical componentry 25 (visible in Figure 3). Each panel 12 has at least one electrical connector disposed at an end of the panel for placing it in electrical communication, for example serial connection, with one or more adjacent panels.

[43] In the embodiment illustrated in Figures 2, 2A and 3, the LED panels comprise a printed circuit board that is formed with an integrated alloy heatsink on its underside. Such boards are referred to as Metal Clad Printed Circuit Boards (MCPCB). MCPCBs have a copper conductor layer upon which the LEDs and other circuit components are mounted and which is etched to implement an LED power supply circuit. A thin electrical insulator layer is located beneath the copper conductor layer. The electrical insulator layer is thermally conductive so that it conducts heat away from the copper conductor layer. A metal cladding layer is disposed against the electrical insulator layer and opposite the copper conductor layer. The metal cladding layer comprises a sheet of conductive metal such as aluminum or copper for conducting heat away from the electrical insulator layer and to the extruded rail 10.

[44] Referring now to Figure 4, there is depicted a first end of a further embodiment of a LED lighting assembly 24 which does not make use of an MCPCB. While it is preferred that the panels be made from MCPCBs it is also possible to implement them using a standard PCB 26 as shown in Figure 4. The elongate and heat conductive support member of the light assembly 24 includes a stiffening member in the form of rail 10. [45] It further includes a metal and thus heat conductive backing plate 28 which is mounted to the rail 10. The elongate and heat conductive support member of this embodiment also includes a heat conductive strip 30. The heat conductive strip 30 is sandwiched between the backing plate 28 and PCB panels 26, which are fastened to the plate 28 by means of push-in / pull- out fasteners 29. The heat conductive strip 30 assists in conducting heat from the PCB panels, to the backing plate 28. Heat is then dissipated from the plate 28 into the air and also to the rail 10.

[46] Figure 5 shows the interconnection of two adjacent panels 26 of the light assembly 24, by means of the electrical connectors 22 located at the end of the adjacent panels. (The adjacent electrical connectors 22 of the first embodiment shown in Figure 2 interconnect in corresponding fashion to that shown in Figure 5.)

[47] Consequently, electricity can be distributed through the interconnected connectors 22 from one panel to another so that the LEDs of each panel can be powered to thereby produce light as required.

[48] Figure 5A shows the underside of a second end of the light assembly 24 (being the end opposite the end shown in Figure 4). In this embodiment the sides of the end of the rail 10 are cutaway to leave a leading insertion end portion 23 of the rail. As will shortly be explained the insertion end portion 23 assists in making a mechanical coupling to a rail support member.

[49] Figure 6 depicts a lighting module 42 wherein three of the light assemblies 24 are supported between two horizontal end support members 44a and 44b. The horizontal end support members may be fastened to a rack or integrated into the pillars 8a, 8b of Figure 1. Alternatively, they may be suspended from a suitable ceiling structure for example. [50] Figure 7 is a close up of an engagement formation, in the form of electromechanical receptacle 46, which is formed into horizontal end support member 44a. The receptacle 46 includes an aperture 38, electrical connector 42 and guide bracket 40. The aperture 38 and electrical connector 42 and guide bracket 40 are shaped and spaced apart to receive the insertion end portion 23 of the rail 10 of light assembly and the electrical connector 22 that is at the end of the light assembly 6 or at the end of the light assembly 24.

[51] Figure 8 is a partially cutaway side view of one end of the plant cultivation installation 2, which is depicted in Figure 1. As can be seen in Figure 8, the insertion end portion 23 of the light assembly 6 is received, through an opening 41 that is formed through the inside wall of pillar 8a, into aperture 38 of support member 44a. The electrical connector 22 of the light assembly 6 is also mated with the electrical connector 42 of the support member 44a. Thus the light assembly 6 is installed both mechanically and electrically to the support member 44a.

[52] The opposing pillar 8b, shown in Figure 1 , is also formed with a similar arrangement to that shown in Figure 8 for the opposite ends 23 of the light rail assemblies. The receptacles that are associated with pillar 8b need not necessarily include a connector guide bracket 40 and electrical connector 42 since the electricity supply to the panels may be provided by connection from one end of the series of interconnected panels only, i.e. the end illustrated in Figure 8.

[53] With reference to Figures 1 and 7, in use a human operator inserts insertion end portion 23 of the lighting assembly 6 into aperture 38 of the receptacle 46 of pillar 8b. The insertion end portion 23 of the other end of the rail is then inserted into the aperture 38 of the receptacle 46 of pillar 8a (as shown in Figure 8). Provided that care is taken, the motion of inserting the end portion 23 of the rail into the aperture 38 achieves interconnection of the electrical connector 22 on the end of the light assembly 6 with the connector 42 that is supported on the connector bracket 40 (as illustrated in Figure 8). This single action mechanical and electrical connection of the light assembly to the receptacle is assisted by the complementary shaping of the aperture 38 to the end profile of the rail. However, other arrangements, for example a number of separated guiding surfaces could also be used to ensure correct alignment of the electrical connector at the end of the light assembly with the pillar's electrical connector 42.

[54] With reference to the embodiment of Figures 2 and 3, after installation, power is provided to the light assemblies 6 by virtue of the interconnection of outermost end connectors 22 of the panels 12 with the pillar's electrical connectors 42. Consequently electrical current flows through the panels, which are interconnected, and their LEDs 20 light and illuminate the plants below. As current flows through the panels their various electrical and electronic components heat up and the panels 12 warm. The heat from the panels is conducted away into the rail 10 and the panels 12 and the rail 10 are also cooled by ambient air circulating through the apertures 18, 16 in the panels and the rail. Consequently, the semiconductor junctions of the LEDs 20 remain at a desirably low temperature and the photon output from the LEDs does not fall off undesirably due to elevated temperature. Should an LED of a light assembly 6 fail then the rail can be removed from the receptacles and conveniently replaced with a functional light assembly. The defective panels of the faulty light assembly can then be slid out from the rail 10. The defective panels 12 can then be easily replaced and the repaired light assembly 6 reinstalled.

[55] Consequently, a method according to an embodiment of the present invention involves installing a plurality of light assemblies 6, each into the plant cultivation installation 1. Subsequently, in response to detecting a failure of an LED 20 of one of the light assemblies 6, removing the affected light assembly from the plant cultivation installation by decoupling it from formation 46 of support member 44a and also from support member 44b. The panel 12 associated with the failed LED can then be removed from the affected light assembly 6 and replaced with a functional panel, e.g. one with all LEDs working, to thereby restore functionality to the light assembly 6. The restored light assembly 6 is then replaced in the plant cultivation installation 2.

[56] The steps of installing and reinstalling the light assemblies include preferably mechanically and electrically coupling each light assembly 6 to a support structure (e.g. support structure 44a) of the plant cultivation installation in a single action. It will be realized that where a large number of light assemblies are involved the single action coupling is particularly convenient and time saving. Furthermore, by being able to readily decouple a defective panel from an adjacent panel, by breaking the interconnection between their respective electrical connectors 22, and sliding the panel out, a defective light assembly can be readily returned to full functionality by substituting a properly working panel.

[57] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. The term "comprises" and its variations, such as "comprising" and "comprised of is used throughout in an inclusive sense and not to the exclusion of any additional features.

[58] It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended aims appropriately interpreted by those skilled in the art.

[59] While the light assemblies according to embodiments of the invention have been described primarily in the context of their use for providing light in intensive plant cultivation installations it will be realised that they may also find application in other situations. [60] Throughout the specification and claims (if present), unless the context requires otherwise, the term "substantially" or "about" will be understood to not be limited to the value for the range qualified by the terms.

[61] Any embodiment of the invention is meant to be illustrative only and is not meant to be limiting to the invention. Therefore, it should be appreciated that various other changes and modifications can be made to any embodiment described without departing from the spirit and scope of the invention.

[62] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[63] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention. [64] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments may be used in any combination.

Claims

CLAIMS:

1. A light assembly comprising:

an elongate and heat conductive support structure;

one or more elongate panel assemblies coupled to said support structure for heat conduction thereto;

2. A light assembly according to claim 1 , wherein the one or more elongate panel assemblies comprise at least two panel assemblies and wherein adjacent panels are placed in electrical communication with each other by interconnection of at least one said electrical connector of each panel.

3. A light assembly according to claim 1 or claim 2, wherein the heat conductive support structure includes a metal extrusion including opposed engagement formations holding the one or more elongate panel assemblies.

4. A light assembly according to claim 3, wherein the opposed engagement formations comprise longitudinal slots that receive opposed edges of the panel assemblies.

5. A light assembly according to claim 3 or claim 4, wherein the one or more elongate panel assemblies comprise a number of printed circuit boards (PCBs) coupled to the support structure.

6. A light assembly according to claim 5, wherein the PCBs are coupled to the support structure by means of a plate which is engaged by the metal extrusion.

7. A light assembly according to claim 6, wherein a layer of one or more pieces of heat transfer material are located between the PCBs and the plate for enhancing heat transfer from the PCBs to the plate and thence to the metal extrusion.

8. A light assembly according to any one of claims 1 to 4, wherein the one or more elongate panel assemblies comprise a number of Metal Clad Printed Circuit Boards (MCPCBs).

9. A light assembly according to claim 6 or claim 7, wherein the plate is formed with apertures therethrough to promote air circulation.

10. A light assembly according to claim 8, wherein the MCPCBs are formed with apertures therethrough to promote air circulation.

1 1. A light assembly according to claim 9 or claim 10 wherein the support structure is formed with apertures therethrough to promote air circulation.

12. A plant cultivation installation including:

a plurality of plant growth solution conduits disposed between opposed support members;

a number of light assemblies according to any one of claims 1 to 11 disposed between the opposed support members;

wherein ends of the light assemblies are received into corresponding engagement formations of the opposed support members to thereby provide mechanical and electrical coupling to the light assemblies.

13. An installation according to claim 12, wherein the engagement formations include:

openings receiving the ends of the support structure of each said light assembly; and

an electrical connector mated with said outermost of the electrical connectors of the panel members whereby the light assembly is mechanically and electrically coupled to the support structure.

14. A method for maintaining lighting in a plant cultivation installation comprising the steps of:

installing a plurality of light assemblies, each according to any one of claims 1 to 11 , into the plant cultivation installation;