Note: Descriptions are shown in the official language in which they were submitted.
CA 02604364 2011-10-28
MODULAR LED UNITS
FIELD OF THE INVENTION
This invention relates to lighting fixtures and, more particularly, to the use
of
LED arrays (modules) for various lighting fixtures and applications,
particularly
lighting application for which HID lamps or other common light sources have
most
typically been used.
BACKGROUND OF THE INVENTION
In recent years, the use of light-emitting diodes (LEOs) for various common
lighting purposes has increased, and this trend has accelerated as advances
have been
made in LEOs and in LED arrays, often referred to as "LED modules." Indeed,
lighting applications which previously had been served by fixtures using what
are
known as high-intensity discharge (HID) lamps are now beginning to be served
by
fixtures using LED-array-bearing modules. Such lighting applications include,
among
a good many others, roadway lighting, factory lighting, parking lot lighting,
and
commercial building lighting.
Among the leaders in development of LED-array modules is Philips Lumileds
Lighting Company of Irvine, California. Work continues in the field of LED
module
development, and also in the field of using LED modules for a various lighting
applications. It is the latter field to which this invention relates.
Using LED modules as sources of light in place of HID lamps or other
common light sources is far from a matter of mere replacement. Nearly
everything
about the technology is different and significant problems are encountered in
the
development of lighting fixture and systems utilizing LED modules. Among the
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many challenging considerations is the matter of dealing with heat
dissipation, to
name one example.
Furthermore, use of LED modules for common lighting applications requires
much more than the typical lighting development efforts required in the past
with HID
or other more common light sources. In particular, creating LED-module-based
lighting fixtures for widely varying common lighting applications - such as
applications involving different light-intensity requirements, size
requirements and
placement requirements - is a difficult matter. In general, harnessing LED
module
technology for varying common lighting purposes is costly because of
difficulty in
adapting to specific requirements. There are significant barriers and problems
in
product development.
There is a significant need in the lighting-fixture industry for modular LED
units - i.e., units that use LED modules and that are readily adaptable for
multiple and
varied common lighting applications, involving among other things varying
fixture
sizes, shapes and orientations and varied light intensity requirements. There
is a
significant need for modular LED units that are not only easy to adapt for
varying
common lighting uses, but easy to assemble with the remainder of lighting
fixture
structures, and relatively inexpensive to manufacture.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an improved modular LED unit that
overcoming some of the problems and shortcomings of the prior art, including
those
referred to above.
Another object of the invention is to provide an improved modular LED unit
that is readily adaptable for a wide variety of common lighting uses,
including many
that have predominantly been served in the past by HID lamps or other common
light
sources.
Another object of the invention is to provide an improved modular LED unit
that significantly reduces product development costs for widely varying
lighting
fixtures that utilize LEDO-array technology.
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Another object of the invention is to provide an improved modular LED unit
that facilitates manufacture and assembly of lighting fixtures using LED
modules as
light source.
How these and other objects are accomplished will become apparent from the
following descriptions and the drawings.
SUMMARY OF THE INVENTION
The present invention is a modular LED unit including one or more LED
modules each bearing an array of LEDs and secured with respect to a heat sink,
such
modular LED unit be adaptable for use in a variety of types of lighting
fixtures.
More specifically, the inventive modular LED unit includes a number of LED
modules separately mounted on individual interconnected heat sinks, with each
heat
sink having: a base with a back surface, an opposite surface, two base-ends
and first
and second sides; a plurality of inner-fins projecting from the opposite
surface of the
base; and first and second side-fins projecting from the opposite surface of
the base
and terminating at distal fin-edges, the first side-fin including a flange
hook
positioned to engage the distal fin-edge of the second side-fin of an adjacent
heat sink.
In some embodiments of this invention, each heat sink may also include first
and
second lateral supports projecting from the back surface, each of the lateral
supports
having an inner portion and an outer portion. The inner portions of such first
and
second lateral supports may have first and second opposed ledges,
respectively, which
form a passageway slidably supporting one of the LED modules against the back
surface of the base.
In certain preferred embodiments, each heat sink includes a lateral recess at
the
first side of the base and a lateral protrusion at the second side of the
base. Such
recesses and protrusions of the heat sinks are positioned and configured for
mating
engagement of the protrusion of one heat sink with the recess of the adjacent
heat
sink. The recess is preferably in the outer portion of the first support and
the
protrusion is preferably on the outer portion of the second support.
Preferably, the first and second lateral supports of each heat sink are
preferably
in substantial planar alignment with the first and second side-fins,
respectively. This
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allows a wide back surface to accommodate substantial surface-to-surface heat-
exchange engagement between the LED module against such back surface of the
heat
sink.
In preferred embodiments, the flange hook of the first side-fin is preferably
at
the distal fin-edge of the first side-fin, where it is engaged by the distal
fin-edge of the
second side-fin of an adjacent heat sink. This provides particularly stable
engagement
of two adjacent heat sinks.
In preferred embodiments of this invention, the first and second side-fins are
each a continuous wall extending along the first and second sides of the base,
respectively. It is also preferred that the inner-fins be continuous walls
extending
along the base. The inner-fins are preferably substantially parallel to the
side-fins.
All fins are preferably substantially parallel to one another.
In certain highly preferred embodiments of this invention, at least one inner-
fin is a "middle-fin" having a fin-end that forms a mounting-hole for securing
the
modular LED unit to another object, such as adjacent portions of a lighting
fixture.
The mounting-hole is preferably a coupler-receiving channel. The mounting hole
which is the coupler-receiving channel is configured to receive a coupler,
such as a
coupler in the form of a screw or any similar fastener. In some of such
preferred
embodiments, each heat sink preferably includes two of the middle-fins.
It is further preferred that each middle-fin be a continuous wall that extends
along the base between fin-ends, and that the coupler-receiving channel
likewise
extend continuously between the fin-ends. Such structures, like the rest of
the
structure of the preferred heat sink, is in a shape allowing manufacture of
heat sinks
by extrusion, such as extrusion of aluminum.
In some highly preferred embodiments of this invention, the modular LED unit
includes a plurality of LED modules mounted on corresponding individual heat
sinks,
each heat sink including a base having a heat-dissipation base surface and a
module-
engaging base surface with one of the LED modules against the module-engaging
base surface, and first and second side-fins each projecting along one of two
opposite
sides of the base and each terminating at a distal fin-edge.
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Certain of such modular LED units include a spacer member adjacent to and
interconnected with at least one of the heat sinks by at least one connection
device
holding the spacer member and the adjacent heat sink in side-by-side
relationship.
The spacer member has a spacer base with first and second spacer-base sides,
and at
least one spacer side-fin along one spacer-base side. In some situations, the
spacer
member is between and connected to a pair of the heat sinks of an LED modular
unit,
maintaining such heat sinks in spaced relationship to one another. In other
situations,
the spacer member may be connected to only one heat sink, putting the spacer
member at the end of the modular LED unit.
Such spacer members and selected spacer member placement provide a great
deal of flexibility in lighting-fixture configuration, allowing use of LED
modules of a
previously-chosen "standard" size for fixtures of widely varying dimensions
and light-
output requirements. For example, a fixture of a particular desired dimension
and
light requirement can use a certain number of LED modules, with one or more
spacer
members accommodating unused space an/or spreading the LED modules to temper
the intensity of light output. Spacer members may themselves have "standard"
sizes
and shapes to accommodate a wide variety of LED lighting-fixture
configurations and
sizes.
In modular LED units of the highly preferred embodiments just described, the
first and second side-fins of each heat sink are a male side-fin and a female
side-fin,
respectively and the spacer side-fin is a male side-fin extending along the
first spacer-
base side and terminating at a distal spacer fin-edge. The connection device
includes
a flange hook on the female side-fins to engage the distal fin-edge of the
adjacent
male side-fin of the adjacent heat sink or spacer member. The spacer member
preferably includes an end-part extending from the spacer base at one end
thereof and
a projection extending from the end-part along at least a portion of the
second spacer-
base side and spaced from the second spacer-base side. The connection device
further
includes a spring-clip holding the projection of the spacer member against the
adjacent male side-fin. The projection may take various forms facilitating
interconnection of the spacer member with the adjacent heat sink; for example,
the
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projection may be a tab extending above the second spacer-base side and
parallel to
the spacer side-fin.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a fragmentary perspective view of an LED floodlight fixture
including a modular LED unit in accordance with this invention.
FIGURE 2 is an enlarged fragmentary end-wise perspective view of two
interconnected heat sinks of the modular LED unit of FIGURE 1.
FIGURE 3 is an enlarged fragmentary perspective view of one heat sink and
its associated LED module mounted thereon.
FIGURE 4 is an enlarged fragmentary end-wise perspective view of the
modular LED unit including the space member between a pair of the heat sinks.
FIGURE 5 is an enlarged fragmentary side perspective view of the modular
LED unit of FIGURE 4.
FIGURE 6 is an enlarged fragmentary end-wise perspective view of the
modular LED unit including the space member connected to one heat sink.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGURES 1-3 illustrate a preferred modular LED unit 10 in accordance with
this invention. Modular LED unit 10 has a number of LED modules 12 separately
mounted on individual interconnected heat sinks 14. Each heat sink 14
separately
supports one LED module 12.
Each heat sink 14 has a base 20 with a flat back surface 23, an opposite
surface 24, two base-ends 26, a first side 21 and a second side 22. Heat sink
14 also
includes a plurality of inner-fins 30 projecting from opposite surface 24 of
base 20, a
first side-fin 40 and a second side-fin 50, each of the side-fins also
projecting from
opposite surface 24. First and second side-fins terminate at distal fin-edges
42 and 52,
respectively. First side-fin 40 includes a flange hook 44 at distal fin-edge
42. Flange
hook 44 is positioned to engage distal fin-edge 52 of second side-fin 50 of an
adjacent
heat sink 14.
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Each heat sink 14 also includes a first lateral support 60A and a second
lateral
support 60B projecting from back surface 23 of base 20. First and second
lateral
supports 60A and 60B are in substantial planar alignment with first and second
side-
fins 40 and 50, respectively. Lateral supports 60A and 60B have inner portions
62A
and 62B, respectively, and outer portions 64A and 64B, respectively. Inner
portions
62A and 62B of first and second lateral supports 60A and 60B have first and
second
opposed ledges 66A and 66B, respectively, which form a passageway 16 that
slidably
supports one of LED modules 12 against back surface 23 of base 20, holding
module
12 in firm surface-to-surface heat-transfer relationship therewith.
As further illustrated in FIGURES 2 and 3, each heat sink 14 includes a
lateral
recess 17 at a first side 21 of base 20 and a lateral protrusion 18 at a
second side 22 of
base 20. As best shown in FIGURE 2, recesses 17 and protrusions 18 are
positioned
and configured for mating engagement of protrusion 18 of one heat sink with
recess
17 of the adjacent heat sink. Recess 17 is in outer portion 64A of first
support 60A
and protrusion 18 is on outer portion 64B of second support 60B.
As shown in the drawings, first and second side-fins 40 and 50 are continuous
walls extending along first and second sides 21 and 22, respectively, of base
20.
Inner-fins 30 are also continuous walls extending along base 20. All of such
fins are
substantially parallel to one another.
As seen in the drawings, in each heat sink 14, two of the inner-fins are
adapted
to serve a special coupling purpose - i.e., for coupling to other structures
of a lighting
fixture. These "middle-fins," identified by numerals 32, have coupler-
receiving
channels 38 running the length thereof - from fin-end 34 at one end of each
middle-
fin 32 to fin-end 32 at the opposite end thereof. Channels 38 form mounting-
holes 36
which are used to secure modular LED unit 10 to another object, such as a
frame
member of a lighting fixture. Couplers may be in the form of screws 19, as
shown in
FIGURES 2 and 3.
As already noted, heat sinks 14 are preferably metal (preferably aluminum)
extrusions. The form and features of heat sinks 14 allow them to be
manufactured in
such economical method, while still providing great adaptability for lighting
purposes.
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The characteristics of heat sinks 14 of the modular LED units of this
invention
facilitate their ganging and use in various ways, and facilitate connection of
modular
LED units of various sizes and arrays in a wide variety of lighting fixtures.
FIGURES 4-6 illustrate highly preferred embodiments of modular LED unit
10, illustrating varying uses of a spacer member 70. Spacer member 70 has a
spacer
base 73 with a first spacer-base side 71 and a second spacer-base side 72, and
a spacer
side-fin 74 along spacer-base side 71. Spacer side-fin 74 terminates at a
distal spacer
fin-edge 75. Spacer member 70 also includes an end-part 76 extending from
spacer
base 73 at each end 77 of spacer base 73, and a projection 78 extends from
each of
end-parts 76 along a portion of second spacer-base side 72 at a position
spaced from
second spacer-base side 72. In each embodiment illustrated, a connection
device 15
holds spacer member 70 and an adjacent heat sink 14 in side-by-side
relationship.
FIGURES 4 and 5 show an arrangement in which spacer member 70 is
positioned between and connected to a pair of heat sinks 14, maintaining such
heat
sinks in spaced relationship to one another. One of heat sinks is connected to
spacer
member 70 by the engagement of flange hook 44 over distal spacer fin-edge 75,
in a
female-male relationship. The other heat sink is connected to spacer member 70
by a
pair of spring-clips 13, each of which holds one of projections 78 against
adjacent
male side-fin 50.
FIGURE 6 shows another arrangement in which two spacer members 70 are
each positioned at a respective end of a modular LED unit. One of the spacer
members is attached to its adjacent heat sink by the flange hook/spacer fin-
edge
engagement described above, and the other spacer member is attached to its
adjacent
heat sink by spring-clips 13.
As shown in FIGURE 6, additional spring-clips 13 help secure adjacent heat
sinks together by their placement about adjacent side-fins 50 and 40.
While the principles of the invention have been shown and described in
connection with specific embodiments, it is to be understood that such
embodiments
are by way of example and are not limiting.
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