WO2016071782A1

WO2016071782A1 - Modular led light fitting and components

Info

Publication number: WO2016071782A1
Application number: PCT/IB2015/057429
Authority: WO
Inventors: Karl Rudolf PABST
Original assignee: Pabst Karl Rudolf
Priority date: 2014-11-03
Filing date: 2015-09-28
Publication date: 2016-05-12

Abstract

A light fitting (1) and component bases and co-operating LED modules (11) are provided. A base that has a length and a width includes a base extrusion (2) having at least two laterally spaced integral formations that cooperate in clipping relationship with co-operating formations on a body extrusion (8) forming a body of a co-operating LED module (11) having one or more outwardly directed LED carrying circuit boards. The base has electrical supply conductors extending along the length thereof that connects in the installed position with a circuit board of each LED module (11) to energize the circuit board and LEDs thereon in use. Multiple LED modules (11) may be clipped to the same base extrusion (2) at different longitudinal positions along the length thereof. The electrical supply conductors may be laterally spaced along the length of the base with exposed regions in releasable contact with contacts extending from each LED module (11).

Description

MODULAR LED LIGHT FITTING AND COMPONENTS

CROSS-REFERENCE(S) TO RELATED APPLICATIONS

This application claims priority from South African provisional patent application number 2014/07999, which is incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to a modular LED (light emitting diode) light fitting or luminaire of a type that is commonly used for illumination purposes in what may be relatively large areas, but that may also be used in considerably smaller areas. The invention also relates to components of such a light fitting or luminaire.

BACKGROUND TO THE INVENTION

There is little doubt that LED type of light fittings are highly advantageous from the point of view of the amount of electrical energy that they consume. They are therefore a light source of choice when one considers the carbon footprint of various different forms of lighting. They have an extremely long lifetime provided that their environmental operating conditions do not adversely affect the performance of the individual LEDs that do exhibit a slow deterioration if operating conditions are not sufficiently controlled and generally cool.

Their life expectancy is, provided that they operate under satisfactory conditions, exceptionally long and indeed considerably longer than the somewhat competitive compact fluorescent light units. However, LED light units are rather costly on the comparative basis and there is a rather common tendency for persons to purchase cheaper less efficient light units such as the conventional incandescent light bulbs, standard fluorescent light tubes, or compact fluorescent light units. For many years, conventional fluorescent light tube types of light fittings have been widely used for illuminating large areas such as workspaces and the like. Replacing ordinary fluorescent light tubes with simple replacement tubes is inexpensive and therefore it is not attractive to consider replacing them with substantially more expensive LED light tubes. Replacing fluorescent tubes with substitute LED lighting tubes has proved problematic and costly to the extent that the cost alone is a serious deterrent. Currently available modular LED lighting systems do not offer quick convenient installation and removal specifically with regard to LED modules installed in series in a flexible chain connected relationship.

In this specification of the term "length" as applied to an extrusion means the longitudinal direction of the extrusion irrespective of whether the actual length of a modular unit is greater than or less than the width of the extrusion. The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application. SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention there is provided a light fitting comprising a base that has a length and a width and that includes a base extrusion having at least two laterally spaced integral formations that cooperate in clipping relationship with co-operating formations on a body extrusion forming a body of a cooperating LED module having an outwardly directed LED carrying circuit board and wherein the base has electrical supply conductors extending along the length thereof that connect in the installed position with a circuit board of each LED module to energize the circuit board and the LEDs thereon in use. Further features of this first aspect of the invention provide for multiple LED modules to be clipped to the same base extrusion at different longitudinal positions along the length thereof; for the electrical supply conductors to be laterally spaced along the length of the base with exposed regions in releasable contact with contacts extending from each LED module; for the base extrusion and the body extrusion of the LED module to be configured so that they can only fit together in one orientation in which any polarity of the electrical supply conductors is maintained and the contacts associated with the LED module are correctly aligned with a correct co-operant electrical supply conductor; for the base and base extrusion to form a single extruded component or alternatively for the base to include at least one base extrusion, side extruded connecting sections and, where there are more than one base extrusion, one or more intermediate connecting extruded sections; for the body extrusion to have multiple spaced apart integral heat dissipating fins extending along its length; and for one of the formations on the base extrusion and the co-operating formations on the body extrusion to be clipping grooves or clipping fins with a clipping formation at or towards their free edges with the other of the formations and co-operating formations being fins with co-operating formations typically at or near their free edges.

Still further features of the first aspect of the invention provide for the base to have provision for receiving one or more fluorescent light tubes as an alternative to the LED modules; for the length of the base to be selected so as to be capable of receiving along its length a maximum integral number of cooperating LED modules; for the light fitting to have a translucent protective cover that can also be an extrusion; for ends of the light fitting to be defined by end caps or end plates that can conveniently be injection moulded; and for the body extrusion and also optionally the base extrusion to be made of a suitably heat conductive material that is conveniently a suitable aluminium material having appropriate heat dissipation properties.

In the preferred instance in which the base is an extrusion of an aluminium or other electrically and heat conductive material, the longitudinally extending conductors are held captive within a separate inwardly lipped channel of electrically insulating material that itself is held captive within an inwardly lipped locating channel of the electrically conductive base extrusion.

In other instances in which the base is made of an electrically insulating material such as a suitable plastics material, longitudinally extending electrical conductors can simply be held captive within an inwardly lipped channel formed in the extrusion process.

Any power supplies or transformers can be mounted to the base in any suitable position that may be on a reverse surface of the extrusion but will most commonly be on the obverse surface thereof from which laterally spaced integral clipping fins extend. Alternatively, such power supplies or transformers may be carried by one or other end caps.

In accordance with a second aspect of the invention there is provided a base of a light fitting adapted for use as a base of a light fitting as defined in the first aspect of the invention. In accordance with a third aspect of the invention is provided an LED module adapted for use as an LED module of a light fitting as defined in the first aspect of the invention.

This invention thus provides an effective and economic means to produce rigid LED light fittings of various lengths ranging from about 100 mm to over 6000 mm.

In order that the above and other features of the invention may be more fully understood, one embodiment thereof as well as some variations will now be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a schematic underneath isometric view of one form of modular LED light fitting according to the invention with the omission of formations in the form of clipping fins on the base extrusion and co-operating flanges on the body extrusion;

Figure 2 is an enlarged cross-section taken through the light fitting illustrated along line II to II in Figure 1 and showing the configuration of each of the base extrusion and body extrusion;

Figure 3 is an enlarged cross-section taken through the cooperating clipping fins of the base extrusion and flanges of the body extrusion of an LED module and showing in sectional view one configuration of spring-loaded pin contacts engaging electrical supply conductors in the base extrusion;

Figure 4 is a detailed cross-section showing one alternative form of contact in engagement with electrical supply conductors in the base extrusion; Figure 5 is similar to Figure 4 but showing a further alternative form of contact in engagement with electrical supply conductors in the base extrusion;

Figure 6 is an end view of one alternative configuration of body extrusion; Figure 7 is an end view of a further alternative configuration of body extrusion;

Figure 8 is a view similar to Figure 3 but showing a different base extrusion that has the clipping fins replaced by clipping grooves and the body extrusion is made of an electrically insulating material;

Figure 9 is an end view of an alternative body extrusion and translucent protective cover; Figure 10 is a view similar to Figure 1 but of a Troffer type of light fitting according to the invention;

Figure 1 1 is a cross-section taken along line XI to XI in Figure 10; and,

Figure 12 is a cross-section similar to Figure 1 1 but taken through an alternative body of a Troffer type of light fitting as illustrated in Figure 10.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

In the embodiment of the invention illustrated in Figures 1 to 3 of the drawings, a light fitting (1 ) comprises a base in the form of a base extrusion (2) of aluminium having at least two integral laterally spaced formations in the form of clipping fins (3) each of which has an outwardly directed ridge (4) towards its free edge (5) (see Figure 3).

Inwardly directed ridges (6) are carried by integral flanges (7) on a cut length of body extrusion (8) also of aluminium. These inwardly directed ridges form clipping formations that cooperate in clipping relationship with the ridges on the clipping fins (3) of the base extrusion such that the LED body extrusion can be simply clipped and undipped from its operative position on the base extrusion. The body extrusion has multiple integral heat dissipation fins (9) extending along its length and spaced apart across its width.

The body extrusion thus forms the body of an LED module (1 1 ) (see Figure 1 ) and has an outwardly directed LED carrying circuit board (12) on its surface opposite that from which the flanges (7) and heat dissipation fins (9) extend.

The base extrusion has electrical supply conductors (13) extending along the length thereof that connect, in the installed position, with the circuit board of each LED module to energize the circuit board and the LEDs thereon in use. The base extrusion, being of aluminium that is both electrically and heat conductive, results in the longitudinally extending supply conductors (13) being held captive within separate extruded inwardly lipped channels (14) of electrically insulating material each of which is itself held captive within an integral inwardly lipped locating channel (15) of the electrically conductive base extrusion. The electrical supply conductors in the extruded base are connected to an electrical power source of any suitable voltage to provide electrical power to the printed circuit boards of the LED modules via spring loaded electrical contacts (17) connected to the printed circuit board and engaging exposed regions of the electrical supply conductors (13). The electrical current can be either alternating current (AC) or direct current (DC) and in the event that it is DC current, the base and body extrusions are designed so as to prevent any reverse polarity connection, preferably through the use of a suitable mechanical interference barrier. In this embodiment of the invention the mechanical interference barrier is an arrangement of cooperating fins and a transverse barrier fin (18) projecting inwards from the inner surface of one of the clipping fins (3) that cooperates with a side fin (19) on one side of the body extrusion that is substantially shorter than a corresponding side fin (21 ) on the other side of the body extrusion. The interaction between the fins and the barrier fin ensure that the body extrusion can be installed in the base extrusion in only one longitudinal orientation.

Multiple LED modules (1 1 ) may thus be clipped to the same base extrusion at different longitudinal positions along the length thereof, as will be quite apparent from a reference to Figure 1 of the drawings. The length of the base may therefore be selected so as to be capable of receiving along its length a predetermined maximum integral number of cooperating LED modules all of which do not have to be installed at any one time, depending on the lighting requirements and affordability of purchasing a full complement of LED modules.

The light fitting may have a translucent protective cover (25) that can also be an extrusion that can clip into place as well as an end cap (26) at each end of the light fitting that can be either translucent or opaque to any required extent. The end caps can conveniently be made by injection moulding a suitable plastics material.

The extruded base is thus of such a design that it can be of any length and receive any number of LED modules that themselves can be of any required length and illuminating strength within the limitations imposed by the technology employed and tied up with the brightness of the individual LEDs and the heat dissipation characteristics of the aluminium body extrusions that act as heat sinks. Typical and practical lengths for the extruded base for domestic, office, warehouse, factory and many other applications may for instance vary between 200 mm and 1800 mm and even longer.

Any power supplies or transformers required can be mounted to the base in any suitable position that may be on a reverse surface of the base extrusion but will most commonly be on the obverse surface thereof from which the laterally spaced integral clipping fins extend. Of course, any appropriate power supply circuitry can also be embodied in the printed circuit board of an LED module. A single power supply may be provided for multiple light fittings; one or more for all the LED modules in a single light fitting; or a power supply may be provided for each LED module. The advancement of technology may well dictate which of these arrangements is most cost effective.

The extruded base may consist of various materials including other suitable metals, metal alloys, plastics, resins, etc and, in instances in which the base is made of an electrically insulating material such as a suitable plastics material, longitudinally extending electrical conductors can simply be held captive within an inwardly lipped channel formed in the plastic material during the extrusion process of any other suitable retaining formations. Also, the electrical conductors in the extruded base may be of various designs and consist of various conductive materials. One variation is shown in Figure 4 in which a longitudinally extending electrical supply conductor (31 ) is of a top hat shape in cross-section orientated on its side so that the "top" of the top hat shape (32) can contact an electrical supply conductor (33) extending transversely into a groove formation with the electrical supply conductor on one side thereof.

A further alternative is shown in Figure 5 in which a flat electrically conductive strip (35) is held in an inwardly lipped sidewall of a groove (36) formed in the extrusion process. In this instance the conductor (37) will need to adopt a shape that can pass around the inwardly projecting edge of the flange (38) of the groove that locates the electrically conductive strip.

Of course, more than two longitudinally extending supply conductors may be provided in order to supply electrical power to the LED module, for example to achieve a dimmable lighting effect, or to enable other functions such as light colour changes, etc.

The LED module is not size restricted and may be of any practical size. The module body may also act as a heat sink for the printed circuit board. Nevertheless, the module body may consist of various materials such as metals, metal alloys, plastics, resins, etc. The LED module body is not limited in design with regard to printed circuit board orientation. More than one printed circuit board orientation may be achieved by incorporating various or multiple angles of printed circuit board mounting surfaces on the module body.

Thus, as illustrated in Figure 6, there may be two flat surfaces (39) inclined to each other and each having its own LED carrying printed circuit board.

Figure 7, on the other hand, shows an extrusion that has three flat surfaces (41 ) inclined to each other for receiving printed circuit boards. Incorporating multiple mounting surfaces at various angles in the LED module enables various light distribution possibilities such as split light intensity, split light colours, limited area lighting, light projection angles, etc. to be achieved. This is at least partially consequent on the fact that LEDs do not emit light in a three dimensional manner but tend to emit it in a generally single direction.

Figure 8 illustrates a base extrusion (42) made of electrically insulating material such as a suitable plastic material in which the clipping fins have been replaced by formations in the form of clipping grooves (43). The clipping grooves receive in clipping relationship, headed formations (44) on the terminal edges of lateral fins (45) integral with a body extrusion (46) of the LED module that is made of an electrically and heat conductive material such as a suitable aluminium, as described above. Figure 8 also illustrates an alternative mechanical barrier to prevent the body extrusion from being installed in any longitudinal orientation other than a correct one and in this instance an arrangement of a shorter fin (47) and a longer fin (48) on the body extrusion are employed in combination with a longer fin (51 ) co-operating with the shorter fin (47) on the base extrusion. Figure 8 still further shows three longitudinally extending electrical supply conductors (52) that are, as a result of the fact that the base extrusion is made of electrically insulating material, simply installed directly in squat inwardly lipped channels (53) in the base extrusion.

Figure 9 shows an alternative form of base extrusion (55) having considerably longer lateral fins (56) extending away from the base itself so that a considerably narrower, and therefore less costly, translucent extrusion can be used as a protective cover (57).

It is also within the scope of this invention that the base be provided with a facility in the form of terminal connectors and optionally a suitable ballast for receiving and energizing one or more fluorescent light tubes as an alternative to the LED modules. This arrangement would be such that the fluorescent light tube can be replaced or even supplemented by one or more LED modules according to the invention as and when the responsible person wishes to upgrade the light fitting.

It will be understood that numerous other variations may be made to the embodiments of the invention described above without departing from the scope hereof. In particular, as shown in Figure 10, the light fittings may be made to be recessed in a ceiling which may be a dropped or false ceiling in well-known manner in the form commonly referred to as Troffer light fittings. A Troffer light fitting has a squat box shaped base (61 ) configured to be flush with a ceiling in the installed condition and have a flat light diffuser (62) parallel to, or coplanar with, the ceiling.

The Troffer type of light fitting may, as illustrated in Figure 1 1 , may incorporate one, two or three base extrusions (63) (two being illustrated in Figure 1 1 ) extending parallel to each other that are affixed to a prefabricated sheet metal Troffer box (64) with the individual LED modules (65) clipped into place in the base extrusions, as described above and as shown by way of example in Figure 10.

Alternatively, as shown in Figure 12, the base extrusions (66), in this instance there being three in number, may actually form parts of the Troffer base itself with the base extrusions (66) being interconnected by intermediate and side extruded connecting sections (67). The base extrusions and connecting sections may be secured to each other at both ends by end plates (68).

It should be noted that Troffer light fittings make up quite a substantial portion of the lighting requirements of commercial, governmental buildings and educational institutions.

Throughout the specification and claims unless the contents requires otherwise the word 'comprise' or variations such as 'comprises' or 'comprising' will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

CLAIMS:

1 . A light fitting comprising a base that has a length and a width and that includes a base extrusion having at least two laterally spaced integral formations that cooperate in clipping relationship with co-operating formations on a body extrusion forming a body of a cooperating LED module having an outwardly directed LED carrying circuit board and wherein the base has electrical supply conductors extending along the length thereof that connect in the installed position with a circuit board of each LED module to energize the circuit board and LEDs thereon in use.

2. A light fitting as claimed in claim 1 in which multiple LED modules are clipped to the same base extrusion at different longitudinal positions along the length thereof.

3. A light fitting as claimed in either one of claims 1 or 2 in which the electrical supply conductors are laterally spaced along the length of the base with exposed regions in releasable contact with contacts extending from each LED module.

4. A light fitting as claimed in any one of the preceding claims in which the base extrusion and the body extrusion of the LED module are configured so that they can only fit together in one orientation in which any polarity of the electrical supply conductors is maintained and contacts associated with the LED module are correctly aligned with a correct co-operant electrical supply conductor.

5. A light fitting as claimed in any one of the preceding claims in which the base and base extrusion form a single extruded component.

6. A light fitting as claimed in any one of claims 1 to 4 in which the base includes at least one base extrusion, side extruded connecting sections and, where there are more than one base extrusion, one or more intermediate connecting extruded sections.

7. A light fitting as claimed in any one of the preceding claims in which the body extrusion has multiple spaced apart integral heat dissipating fins extending along its length.

8. A light fitting as claimed in any one of the preceding claims in which the formations on the base extrusion and the co-operating formations on the body extrusion are clipping grooves or clipping fins with a clipping formation at or towards their free edges with the other of the formations and co-operating formations being fins with co-operating formations near their free edges.

9. A light fitting as claimed in any one of the preceding claims in which the base has provision for receiving one or more fluorescent light tubes as an alternative or in addition to the LED modules.

10. A light fitting as claimed in any one of the preceding claims in which ends of the light fitting are defined by end caps or end plates.

1 1 . A light fitting as claimed in any one of the preceding claims in which the body extrusion is made of a suitably heat conductive material having appropriate heat dissipation properties.

12. A light fitting as claimed in any one of the preceding claims in which the base extrusion is an extrusion of an aluminium or other electrically and heat conductive material and the longitudinally extending conductors are held captive within a separate inwardly lipped channel of electrically insulating material that itself is held captive within an inwardly lipped locating channel of the electrically and heat conductive base extrusion.

13. A light fitting as claimed in any one of the preceding claims in which the base extrusion is made of an electrically insulating material and longitudinally extending electrical conductors are held captive within inwardly lipped channels formed in the extruded section.

14. A base of a light fitting adapted for use as a base of a light fitting as claimed in any one of claims 1 to 13.

15. An LED module adapted for use as an LED module of a light fitting as claimed in any one of claims 1 to 13.