Note: Descriptions are shown in the official language in which they were submitted.
COMPACT LED WORK LIGHT
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of United States
Patent Application No.
13/270,808 filed October 11, 2011 which is a continuation of United States
Patent No. 8,033,681
issued October 11, 2011 which is a continuation of United States Patent No.
7,553,051 issued
June 30, 2009 which claims the benefit of the filing date of United States
Patent Application No.
60/521,240 filed 18 March 2004, Application No. 60/521,680 filed 16 June 2004,
Application
No. 60/521,689 filed 17 June 2004, Application No. 60/521,738 filed 28 June
2004, and
Application No. 60/521,888 filed 17 July 2004 under the title LED Work Light.
This application
is also a continuation in part of United States Patent Application No.
12/289,782 which is a
continuation of PCT/CA2007/000802 filed May 4, 2007 which is a continuation in
part of United
States Patent No. 7,553,051 issued June 30, 2009 which claims the benefit of
the filing date of
United States Patent Application No. 60/521,240 filed 18 March 2004,
Application No.
60/521,680 filed 16 June 2004, Application No. 60/521,689 filed 17 June 2004,
Application No.
60/521,738 filed 28 June 2004, and Application No. 60/521,888 filed 17 July
2004 under the title
LED Work Light.
FIELD OF THE INVENTION
[0002] The application relates to work lights. More particularly it
relates to LED work
lights.
BACKGROUND OF THE INVENTION
[0003] Work lights, often known as "trouble lights", are widely used
in automotive repair
shops and other repair settings and construction settings. Such work lights
are often in a form
that can alternatively be handheld or hung from a suitable elevated object
such as a raised
automobile hood.
[0004] Incandescent work lights have been in use, but they have some
drawbacks.
Incandescent work lights can be hot to the touch. Also, work lights are all
too often dropped or
knocked down and fall onto a hard surface, and this often results in breakage
of an incandescent
bulb or its filament. An additional drawback of incandescent work lights is a
safety hazard that
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results from the possibility of the bulb breaking with its hot filament in
close proximity to
flammable material such as spilled flammable liquid if the work light suffers
a fall.
[0005] Fluorescent work lights exist and they have advantages over
incandescent work
lights, namely greater energy efficiency and a reduced hazard of igniting
flammable materials if they
suffer a fall. However, fluorescent work lights can experience breakage of
their bulbs if they suffer
a fall. Although breakage of an operating fluorescent bulb is not as likely to
ignite nearby
flammable materials as breakage of an incandescent bulb is, there is still a
slight chance that a
fluorescent bulb can ignite adjacent flammable materials if broken while
operating since fluorescent
lamps normally have hot electrodes while they are operating. There are
fluorescent work lights that
have impact cushioning means included to increase their ability to survive
falls, but they may
experience breakage of their bulbs if they fall onto a hard surface.
[0006] LED work lights are better able to survive falls than are work
lights that have glass
bulbs. Furthermore, LEDs do not generally operate with parts hot enough to
ignite flammable
materials, so even falls that do result in breakage are less likely to cause
fires than are similar falls of
.. work lights that have glass bulbs.
[0007] LED work lights of increasing light intensity are relatively
costly. LED work lights
of increasing light intensity utilize LEDs that can produce sufficient heat to
damage the LEDs or
other circuitry. Battery operated LED work lights can have limited run times
and can be fairly large.
[0008] As described further herein some features of some aspects of
the invention will
address some of the issues raised above. Other features and other aspects will
address other issues
with existing LED lights to provide alternatives or improvements thereto.
SUMMARY OF ASPECTS OF THE EMBODIMENTS
[0009] In a first aspect embodiments can provide a work light having a
work light body.
The work light body includes a handle section and a light head section, an
elongate housing
extending through the handle section and the light head section, a battery
compartment and a
component chamber longitudinally aligned within the housing, a battery within
the battery
compartment, an LED circuit board assembly extending longitudinally within the
housing and
having a substrate layer, an external component layer on a first side of the
substrate layer, and a
.. driving component layer on an opposing second side of the substrate layer,
wherein an overlapping
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portion of the LED circuit board assembly is placed in close proximity to the
battery over the battery
compartment, at least one LED on the external component layer, the external
component layer
facing transaxially outwardly from the housing such that light emitting from
the LED emits from the
light head section, and at least one driving component on the driving
component layer, all driving
components on the driving components layer placed on an extending portion of
the LED circuit
board assembly that extends from the overlapping portion over the component
chamber.
[0010] Close proximity can be less than the depth of at least one
driving circuit component
in the driving circuit layer. Close proximity can be less than the depth of
all driving circuit
components in the driving circuit layer.
[0011] The work light can have a lens assembly over the LED circuit board
assembly, the
lens assembly including a lens over each LED.
[0012] The substrate layer can be formed of a thermally conductive
material, and the
substrate can be in thermal contact with the housing, and the housing can be a
heatsink formed of
thermally conductive material.
[0013] The work light body can also include a charging port for receiving
external power to
the work light body, dual mode circuitry within the external component layer
and driving circuit
layer to charge the battery from the charging port when receiving external
power through the
charging port, and to power the LED when the work light is receiving power
from the charging port
and when the work light is not receiving power from the charging port, and a
tether port about the
charging port, and, the work light can also include a power cable assembly
comprising a power
cable, a charging port connector at a first end of the power cable, the
charging port connector
compatible with the charging port to provide power through the power cable to
the work light body,
and a tether port connector about the charging port connector at the first end
of the power cable.
The tether port connector is compatible with the tether port to provide a
manually operable tether
connection between the power cable assembly and the work light body. The
tether connection is
such that the work light body is mechanically restrained by the power cable
assembly when tether
connected, and the charging port and charging port connector are maintained
connected when the
work light body and power cable assembly are tether connected.
[0014] In a further aspect embodiments can provide a work light
comprising a work light
body including a handle section and a light head section, an elongate housing
extending through the
handle section and the light head section, an LED circuit board assembly
having a substrate layer
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and an external component layer on a side of the substrate layer, the
substrate layer formed of a
thermally conductive material, the substrate layer is in thermal contact with
the housing, and the
housing is a heatsink formed of thermally conductive material, andl at least
one LED on the external
component layer, the external component layer facing transaxially outwardly
from the housing such
that light emitting from the LED emits from the light head section.
[0015] A layer of the LED circuit board assembly other than the
substrate layer can be
between the substrate layer and the housing, such layer can be electrically
resistive with low thermal
resistance. The substrate can be formed of metal and the LED circuit board
assembly can be a metal
core LED circuit board assembly.
[0016] The housing can be a single-piece unit. The housing can include
longitudinal
grooves trapping longitudinal edges of the substrate layer to hold the
substrate layer in thermal
contact with the housing.
[0017] The work light can have a driving component layer on an
opposing side of the
substrate layer, and at least one driving component on the driving component
layer.
[0018] In another aspect embodiments can provide a work light including a
work light body
comprising, a handle section and a light head section, at least one LED facing
such that light
emitting from the LED emits from the light head section, a charging port for
receiving external
power to the work light body, a battery to power the LED, dual mode circuitry
to charge the battery
from the charging port when receiving external power through the charging
port, and to power the
.. LED when the work light is receiving power from the charging port and when
the work light is not
receiving power from the charging port, and a tether port about the charging
port. The work light
can further include a power cable assembly comprising a power cable, a
charging port connector at a
first end of the power cable, the charging port connector compatible with the
charging port to
provide power through the power cable to the work light body, and a tether
port connector about the
charging port connector at the first end of the power cable. The tether port
connector is compatible
with the tether port to provide a manually operable tether connection between
the power cable
assembly and the work light body. The tether connection is such that the work
light body is
mechanically restrained by the power cable assembly when tether connected, and
the charging port
and charging port connector are maintained connected when the work light body
and power cable
assembly are tether connected.
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[0019] The tether port and tether port connector can include a
threaded projection and a
threaded cap. The charging port and charging port connector can include an
electrical plug and
socket.
[0020] The work light can have an electrical plug on a second end of
the power cable for
connection to an external power source. The power cable assembly can have a
cord reel about
which the power cable is reeled.
[0021] Other aspects of the invention including for example methods
of use will be evident
from the detailed description hereof
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a better understanding of the present invention and to show more
were clearly
how it may be carried into effect, reference will now be made, by way of
example, to the
accompanying drawings which show the embodiments in which:
[0023] FIG. 1 is a perspective view of an example embodiment of an
LED work light,
[0024] FIG. 2 is an exploded perspective view of the LED work light
of FIG. 1,
[0025] FIG. 3 is a longitudinal cross-section of the work light of FIG. 1,
[0026] FIG. 4 is a perspective view of a perspective view of an
alternative housing and LED
circuit board assembly for use in an LED work light such as the LED work light
of FIG. 1
[0027] FIG. 5a is a perspective view of an example embodiment of an
LED circuit board
assembly of the work light of FIG. 1,
[0028] FIG. 5b is a detailed example longitudinal cross-section of a
portion of a metal core
printed circuit board which can be used in the LED circuit board assembly of
FIG. 5a,
[0029] FIG. 6 is a side view of another example embodiment of an LED
work light,
[0030] FIG. 7 is an end view of the LED work light of FIG. 6,
[0031] FIG. 8 is a perspective view of a example dual mode embodiment
of an LED work
light with a power cable tethered to a work light body,
[0032] FIG. 9 is a perspective view of the LED work light of FIG. 8
with the power cable
untethered from the work light body,
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[0033] FIG. 10 is an example embodiment of an electrical circuit
schematic diagram for use
in the LED work light of FIG. 8, and
[0034] FIG. 11 is a further example embodiment of a dual mode LED work
light.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0035] Referring generally to the FIGs. various embodiments of LED work
lights are shown.
For example, an embodiment has a work light having a work light body. The work
light body
includes a handle section and a light head section, an elongate housing
extending through the handle
section and the light head section, a battery compartment and a component
chamber longitudinally
aligned within the housing, a battery within the battery compartment, an LED
circuit board assembly
extending longitudinally within the housing and having a substrate layer, an
external component
layer on a first side of the substrate layer, and a driving component layer on
an opposing second side
of the substrate layer, wherein an overlapping portion of the LED circuit
board assembly is placed in
close proximity to the battery over the battery compartment, at least one LED
on the external
component layer, the external component layer facing transaxially outwardly
from the housing such
that light emitting from the LED emits from the light head section, and at
least one driving
component on the driving component layer, all driving components on the
driving components layer
placed on an extending portion of the LED circuit board assembly that extends
from the overlapping
portion over the component chamber.
[0036] Close proximity can be less than the depth of at least one
driving circuit component
.. in the driving circuit layer. Close proximity can be less than the depth of
all driving circuit
components in the driving circuit layer.
[0037] The work light can have a lens assembly over the LED circuit
board assembly, the
lens assembly including a lens over each LED.
[0038] The substrate layer can be formed of a thermally conductive
material, and the
substrate can be in thermal contact with the housing, and the housing can be a
heatsink formed of
thermally conductive material.
[0039] The work light body can also include a charging port for
receiving external power to
the work light body, dual mode circuitry within the external component layer
and driving circuit
layer to charge the battery from the charging port when receiving external
power through the
.. charging port, and to power the LED when the work light is receiving power
from the charging port
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and when the work light is not receiving power from the charging port, and a
tether port about the
charging port, and, the work light also has a power cable assembly comprising
a power cable, a
charging port connector at a first end of the power cable, the charging port
connector compatible
with the charging port to provide power through the power cable to the work
light body, and a tether
port connector about the charging port connector at the first end of the power
cable. The tether port
connector is compatible with the tether port to provide a manually operable
tether connection
between the power cable assembly and the work light body. The tether
connection is such that the
work light body is mechanically restrained by the power cable assembly when
tether connected, and
the charging port and charging port connector are maintained connected when
the work light body
and power cable assembly are tether connected.
[0040] In another embodiment a work light has a work light body
including a handle section
and a light head section, an elongate housing extending through the handle
section and the light head
section, an LED circuit board assembly having a substrate layer and an
external component layer on
a side of the substrate layer, the substrate layer formed of a thermally
conductive material, the
substrate layer is in thermal contact with the housing, and the housing is a
heatsink formed of
thermally conductive material, andl at least one LED on the external component
layer, the external
component layer facing transaxially outwardly from the housing such that light
emitting from the
LED emits from the light head section.
[0041] A layer of the LED circuit board assembly other than the
substrate layer is between
the substrate layer and the housing, such layer can be electrically resistive
with low thermal
resistance. The substrate is formed of metal and the LED circuit board
assembly can be a metal core
LED circuit board assembly.
[0042] The housing is a single-piece unit. The housing has
longitudinal grooves trapping
longitudinal edges of the substrate layer to hold the substrate layer in
thermal contact with the
housing.
[0043] The work light has a driving component layer on an opposing
side of the substrate
layer, and at least one driving component on the driving component layer.
[0044] In another embodiment a work light hasa work light body having
a handle section
and a light head section, at least one LED facing such that light emitting
from the LED emits from
the light head section, a charging port for receiving external power to the
work light body, a battery
to power the LED, dual mode circuitry to charge the battery from the charging
port when receiving
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external power through the charging port, and to power the LED when the work
light is receiving
power from the charging port and when the work light is not receiving power
from the charging
port, and a tether port about the charging port. The work light has a power
cable assembly
comprising a power cable, a charging port connector at a first end of the
power cable, the charging
port connector compatible with the charging port to provide power through the
power cable to the
work light body, and a tether port connector about the charging port connector
at the first end of the
power cable. The tether port connector is compatible with the tether port to
provide a manually
operable tether connection between the power cable assembly and the work light
body. The tether
connection is such that the work light body is mechanically restrained by the
power cable assembly
when tether connected, and the charging port and charging port connector are
maintained connected
when the work light body and power cable assembly are tether connected.
[0045] The tether port and tether port connector has a threaded
projection and a threaded
cap. The charging port and charging port connector have an electrical plug and
socket.
[0046] The work light can have an electrical plug on a second end of
the power cable for
connection to an external power source. The power cable assembly can have a
cord reel about
which the power cable is reeled.
[0047] Additional details of these and other embodiments will now be
described.
[0048] Referring to FIG. 1, a work light 100 has work light body 101
having a handle
section 102 and a light head section 103. The light head section 103 has a
transparent cover 104
through which light is emitted from the work light 100.
[0049] A switch enclosure 105 encloses a switch cover 106. The switch
cover 106 is
malleable and allows actuation of a switch 107 (see FIG. 2 for example) to
control the emission of
light from the head section 103 of the work light 100. For example, the switch
cover 106 may be
formed from rubber.
[0050] A hook 108 extends from the work light body 101. The hook 108 is
mounted to the
work light body 101 to provide a rotatable mount 109 to allow the hook 108 to
lay flat against the
work light body 101 when the hook 108 is not in use. For example, the hook 108
can lay flat against
the head section 103. As shown in the FIGS., the mount 109 provides pin 110
extending
transaxially from the hook 108 into holes 111 in opposing plates 112 extending
axially away from
the work light body 101.
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[0051] In addition to allowing for rotation against and away from the
work light body 101,
the rotatable mount 109 can allow for additional degrees of freedom for the
hook 108. For example,
the rotatable mount 109 can itself be mounted to the work light body 101 such
that the mount 109
can rotate about an axis of the work light body 101. For example the plates
112 can be mounted on
an axial pin 113 (FIG. 3), extending into the work light body 101 on an axis
aiming through the head
section 103 and the handle section 102. Other mounts, not shown, could be
used, such as a universal
ball and socket joint. Such a hook 108 and mount 109 can provide a great deal
of versatility and
utility for hands-free positioning of the work light 100. Although hands-free
positioning of a work
light can be desirable, it is not necessary to provide a means for hands-free
positioning of the work
light 100 in order to take advantage of all the features described herein for
work lights.
[0052] Referring to FIG. 2, the work light body 101 has a housing 201,
end caps 203, 205,
bumpers 207, battery 209, LED circuit board assembly 211, lens assembly 213,
switch cover 106,
switch enclosure 105, and transparent cover 104. Various screws 214 are
employed to fix element
of the work light 100 to the housing 201, such as the end caps 203, 205.
[0053] Referring to FIG. 3, the work light 100 has a battery compartment
301, substantially
filled by battery 209, and a component chamber 303. The battery compartment
301 and component
chamber 303 are longitudinally aligned within the housing 201. Opposing ends
305 and 307 of the
housing 201 are enclosed by the end caps 203, 205. The battery compartment 301
and component
chamber 303 are between the end caps 305, 307.
[0054] In the embodiments shown in the FIGS. herein the housing 201 is a
rigid elongate
single-piece construction. For example, the housing 201 can be formed from an
extrusion process.
Alternative embodiments of the housing are possible where the end caps 203,
205, or portions
thereof, are also incorporated into the housing 201 in a single piece
construction with the battery
inserted transaxially into the housing and moved into a battery compartment
rather than through an
end of the housing. As necessary other manufacturing processes such as
moulding may be used.
[0055] In the FIGS the battery 209 is shown as a single unit. The
battery 209 can comprise
multiple battery cells and associated terminals and wiring, not independently
shown, packaged in a
plastic wrap 210, preferably shrink-wrap, to form a single unit as is known to
those skilled in the
battery art. As shown, in the FIGS, battery cells are arranged into a battery
209 side-by-side and
longitudinally to form an elongate battery 209 having an obround axial cross-
section. A battery 209
could be formed a single cell, or separate cells unpackaged as a single unit.
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[0056] Referring to FIGS. 3, 5a and 5b, battery 209 is in the battery
compartment 301.
LED circuit board assembly 211 has a substrate layer 401 between an external
component layer
403 and a driving circuit layer 405. Components 406 requiring external
interaction, such as switch
107 and LEDs 409 are mechanically and electrically connected on to the
external component layer
403, such as by solder; while, driving circuitry components 407 are
mechanically and electrically
connected to the driving circuit layer 405, such as by solder.
[0057] By placing components 407 that do not require external
interaction on the driving
circuit layer 405, rather than on the external component layer 403, the
overall length of the LED
circuit board assembly 211 can be reduced.
[0058] In addition, components 406, 407 on both the layers 403 and 405 can
generate heat.
Dividing the components 406, 407 between the layers 403 and 405 can allow for
less heat build-
up.
[0059] The circuit board assembly 211 longitudinally overlaps the
battery 209 and extends
over the component chamber 303. While the external components 406 are spread
over the length
of the LED circuit board assembly 211, the driving circuit components 407 on
the driving circuit
layer 405 are placed on that portion 408 of the driving circuit layer 405 that
extends over the
component chamber 303 such that the components 407 are provided with some air
circulation to
dissipate heat from the components 407. The driving circuit components 407 are
in fluid
communication with the chamber 303. By overlapping the LED circuit board
assembly 211 and the
battery 209, the overall length of the work light can be reduced, while
allowing for needed battery
size for sufficient operating time between battery charges.
[0060] The components 407 can also extend into the chamber 301. By
placing the
components 407 such that the components extend into the chamber 301, the
substrate layer 401
can be brought into close proximity to the battery 209. Bringing the substrate
layer into close
proximity with the battery 209 can reduce the overall girth of the work light.
[0061] It is recognized that space on the external component layer
403 is particularly limited
about the LEDs 409 when aligning a lens assembly 213 immediately adjacent the
external
component layer 403 for manipulation of light emanating from the LEDs 409. The
lens assembly is
held in alignment by keys projecting into keyways in the end cap 205 and the
switch enclosure 105.
The switch enclosure is held in place with respect to the LED circuit board
assembly 211 and, thus,
LEDs 409 by pins extending from the switch enclosure 105 into holes 451 in the
LED circuit board
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assembly. The end cap 205 holds the LED circuit board assembly in place from
longitudinal
outward movement.
[0062] The housing 201 has opposing longitudinal grooves 221 which
retain the LED
circuit board assembly 211, switch cover 105 and transparent cover 104 for
other than longitudinal
movement. The switch cover 105 and transparent cover 104 are held together in
the grooves 221.
The switch cover 105 and end cap 205 have respective opposing curved slots 331
to receive the
transparent cover 104.
[0063] The housing 201 could have alternate configurations. For
example, The housing
201 could entirely enclose the battery 209 in cross-section while leaving the
component chamber
303 open to the LED circuit board assembly 211.
[0064] There is a corresponding lens 415 in the lens assembly 213
place forward of each
LED 409. The concavo-convex lens of United States Patent Application No.
13/370,808
(continuation of 12/458,018) discussed in particular with regard to FIG. 11
thereof has been found
to be particularly efficient and to provide a particularly uniform beam, and
reference is made to
.. that FIG. The concavo-convex lens of United States Patent Application No.
12/289,782 discussed
in particular with regard to FIG. 2 is shown as an individual lens having
holes for mounting by
screws. It is noted individual lenses 415 could also be mounted about the LEDs
409 by screws to
the LED circuit board assembly 211, or other fastening means within the work
light body 101.
Example optics in place of the lenses 415 are described in United States
Patent Application No.
13/370,808 (continuation of 12/458,018) in particular with regard to FIG. 7
thereof, and reference
is made to that FIG.
[0065] As shown in the FIGS., the housing 201 has an internal
transaxial cross-section
similar to an external transaxial cross-section of the battery 209 to retain
the battery 209 from
lateral movement in the housing 201. Preferably, the battery 209 has a non-
circular cross-section
such that the housing 201 also retains the battery 209 from rotation. The
housing 201 can have
alternate cross-sections different in shape from the cross-section of battery
209; however, the work
light body 101 may be less compact. For example, the housing 201 might have a
rectangular cross-
section; while, the battery 209 is obround or cylindrical. Additional blocks
or spacers, not shown,
may be required to hold the battery 209 in place in such a housing.
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[0066] As shown in the FIGS, the housing 201 forms a channel wall 225
extending about a
substantial portion of the cross-section of the battery 209 to retain the
battery. The transparent
cover, switch enclosure, and a handle cover 226 extend across the channel wall
225 over the
battery 209 to enclose the housing 201.
[0067] The battery 209 can be inserted into and removed from the housing
201 from a first
end 305 of the housing 201.
[0068] Referring to FIG. 4, a housing 501, shown as similar to the
housing 201, can be a
heatsink, for example formed out of a metal such as aluminum. Aluminum
provides a good
combination of cost, weight, and thermal conduction parameters. Anodized
aluminum can provide
additional durability for protection against wear and tear. LEDs, particularly
high power LEDs,
can require independent heat sinking in addition to any heat sinking provided
as part of the LEDs.
[0069] A substrate layer 503, shown as similar to the substrate layer
401 of the LED circuit
board assembly 211, can be metal such that LED circuit board assembly 511 is a
metal core LED
circuit board assembly 511. The implementation of a work light utilizing
housing 501 and
assembly 511 can be otherwise similar to the work light 100, as such like
reference numerals will
be used for similar components and the description of such components will not
be repeated.
[0070] The housing 501 holds substrate layer 503 in thermal contact
with the housing 501.
Other layers, such as layers 403, 405 of the metal core LED circuit board
assembly 511 may be
between the substrate layer 503 and the housing 501 provided the thermal
resistance is sufficiently
low and appropriate electrical resistance is provided between electrical
layers and the housing 501.
[0071] Referring to FIGS. 5a and 5b, example board layers may include
substrate layer
503, electrically insulating layers 621, 623 on either side of the substrate
layer 503. Electrically
insulating layers 621, 623 may be formed from a material such as a polymer
that is electrically
insulating, while thermally conductive in thin layers. Circuit traces form
external component layer
403 and driving component layer 405 on the insulating layers 621, 623. Further
electrically
insulating, thermally conductive layers 625, 627 cover the external component
layer 403 and
driving component layer 405, respectively. It may be most efficient to use a
solder mask for the
layers 625, 627. The solder mask can be left on after use in masking for
application of solder to
apply components to traces in the component layers 403, 405.
[0072] Connections between the external component layer 403 and the driving
component
layer 405 are typically accomplished by vias 650, which are conductive holes
in the LED circuit
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board 211. A via 650 is shown as an example one in a metal core printed
circuit board that is used
for the LED circuit board 211. In a via 650, the external component conductive
layer 403 and the
driving component conductive layer 405 merge into each other as a conductive
layer continuation
651.
[0073] Insulation of the conductive layers 403,405,651 from the metal
substrate 503 is
maintained by the insulating layers 621,623 similarly continuing into each
other through the via 601
as an insulating layer continuation 652. Maintaining insulation from the
substrate 503 is necessary
in order to avoid shorts between the conductive layers 651 of more than one
via 601.
[0074] Referring again to FIG. 4, the substrate layer 503 can be held
in thermal contact with
the housing 501 by trapping opposing longitudinal edges 531, 533 of the
substrate layer 503 in
opposing longitudinal grooves 513 of the housing 501. Heat from the substrate
layer 503 sinks into
the housing 201. The substrate layer 503 in turn sinks heat from the
components in the layers 403,
405. Independent heatsinks are particularly important for components such as
high power LEDs.
[0075] LED circuit board assembly heatsinking to a work light housing
can result in benefits
in assembly. For example, using a housing 501 to both hold and draw heat
through the substrate
layer from the LEDs 409 can reduce complexity in manufacture and placement of
a LED circuit
board assembly 511.
[0076] LED circuit board assembly heatsinking to a work light housing
can be applied to
LED work lights, which do not utilize features of other embodiments described
herein such as, for
example, inline battery compartment and component chamber with overlapping LED
circuit board
assembly. Such LED work lights can include non-battery operated work lights.
However, LED
circuit board assembly heatsinking to a work light housing can provide
synergistic benefits when
applied in conjunction with features of other embodiments described herein
such as, for example,
inline battery compartment and component chamber with overlapping LED circuit
board assembly.
.. For example, other features described herein can provide compact LED work
lights, which compact
lights can further benefit from LED circuit board assembly heatsinking to a
work light housing to
draw away heat in a potentially compact manner.
[0077] Referring again to FIG. 2, the housing 201 incorporates rails
251 on either side of the
housing 201 to which the bumpers 207 are attached. The bumpers 207 provide a
comfortable grip to
a user, while protecting the housing 201 and objects in the environment that
the work light 100 may
- 13 -
contact. The bumpers 207can extend beyond the depth of the housing 201 to
provide additional
comfort and protection.
[0078] Referring to again to FIG. 3, a block 300 extends transaxially
into the housing 201
to stop the battery from further longitudinal movement into the housing 201.
The block 300 is
fixed to the housing 201 by two screws 214. Other means may be used to fix the
block 300 to the
housing 201, such as glue. Alternatively, the block 300 may be formed within
the housing as a
single piece construction.
[0079] End cap 203 encloses first end 305 of the housing 201. The end
cap 203 retains the
battery 209 between the block 300 and the end cap 203 to restrict longitudinal
movement of the
battery within the housing 201. The end cap 203 has a terminal enclosure 223
providing terminals
261 for receiving external power for the battery 209. The battery 209 is also
connected through the
switch 107 to the LEDs 409 for illumination. Wiring connecting between
externally accessible
terminals 261 (one of which is visible in FIG. 3), the battery 209, and socket
contacts 265 has been
omitted for simplicity. Springs or spring loaded tabs, not shown, may be
provided, for example on
the block 300, to bias the battery 209 against the terminal enclosure 223
where simple contacts are
used to make an electrical connection from the terminals 261 to the battery
209, and from the
battery 209 to wiring for the LEDs 409. As will be known to those skilled in
the art many other
connection means may be used to connect electrical power from the terminal
enclosure to the
battery 209, such as springs or spring loaded tabs, not shown, for the
contacts on the terminal
enclosure 223, or wired connectors, not shown.
[0080] The terminal enclosure 223 is longitudinally aligned with the
battery 209 and the
component chamber at an opposing end of the battery 209. This placement of the
battery 209
positions the battery 209 more centrally in the work light body 101 for
balance purposes.
[0081] The terminals 261 can be used to provide external power to the
LED work light 100
for charging the battery. The work light 100 may be placed in a charging
station, not shown, for
charging. Alternatively, the work light 100 may be provide with a charging
port, such as a socket,
not shown, to receive a charging plug on a power cord. An example of a
suitable charging plug and
socket combination is described with respect to work light 701 later herein.
[0082] Contacts 263 on LED circuit board assembly 211 and
corresponding socket contacts
265 on end cap 203 are provided to electrically connect the battery 209 to the
LED circuit board
assembly 211.
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[0083] Referring to FIGS. 6 and 7, a dual-mode work light body 707 has
a tether port 703
about a charging port 705.
[0084] Referring to FIG. 8 and 9, a work light 701 has work light body
707 and also has a
power cable assembly 708 including a power cable 709 terminating at one end in
a tether port
connector 711 to engage the tether port 703 and in a charging port connector
713 to engage the
charging port 705. The tether port 703 and the tether port connector 711 are a
manually operable
tether connection, while the charging port 705 and charging port connector 713
mate to form an
electrical connection. A tether connection between the power cable assembly
708 and the work
light body 707 is a mechanical restraint on the mobility of the work light
body 707 such that the
work light body 707 is restrained from moving beyond the distance allowed by
the power cable
assembly 708.
10085] For example, the tether port 703 can be a tubular projection
719 from end cap 720
about a charging port 705 that is an electrical charging socket 720a. The
tubular projection 719 can
have external threads 721. The charging port connector 713 can be a charging
plug 721a; while the
.. tether port connector 711 can be an internally threaded cap 722 having a
hole 723 fitting about
power cable 709. The hole 723 is of a smaller dimension than the plug 721a
such that the cap 722
maintains the connection between the plug 721a and socket when the cap 722 is
manually threaded
to the tubular projection 1351 to tether the work light 701 to the cable 709
(FIG. 7). The cap 722
can be manually unthreaded to release the work light 701 from the cable 709
(FIG. 8).
[0086] The tether port 703 and tether port connector 711 form a
mechanically durable
connection to maintain the union when work light body 707 is tugged during
use. Alternate
example forms of connection may include a tether port and tether port
connector having a bayonet
mount configuration.
[0087] A manually operable tether connection in combination with a
battery operated work
light body 707 can enable untethered portable use of the work light body 707.
This can be
advantageous for use of the work light body 707 in locations remote from a
power source, or
locations where a power cable is inconvenient. As the work light 701 is dual
mode, the work light
701 can be charging while tethered to maintain a full charge for portable use.
Lithium ion batteries,
and other batteries that do not suffer from memory effects, are particularly
well suited to this
application.
30200380_1INATDOCS
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[0088] The features described herein can provide compact LED work
lights, particularly
heatsink LED work lights, while allowing for batteries that can provide a full
shift of illumination,
for example 8-10 hours of portable use. A compact LED work light can have an
even more
compact work light body where a manually operable tether is used in locations
that shorter
durations of battery only power. This may be particularly true for tethered
applications where the
battery is charging while tethered and available for portable use fully
charged. A tether can be
particularly useful for smaller LED work lights that can be easily misplaced.
[0089] Referring to again to FIG. 8, the LED work light 701 is shown
as receiving power
through the power cable assembly 708 including the cable 709 and a plug 801 at
an end of the
power cable 709. The plug 801 plugs into an external power source, not shown.
For AC external
power source applications a power supply 1304 can be inline with the power
cable 709 to step
down and, possibly rectify and/or regulate, an external power source voltage
to levels usable on an
LED circuit board assembly 211 to charge batteries 209 and power LEDs 409. For
example a
switch mode power supply 803 can be used. The power supply can be integrated
with the plug in a
"wall wart" type power supply configuration.
[0090] Where the work light 701 is to be powered from a car or other
external battery, the
plug 801 can be an automotive DC plug, not shown, possibly including a DC-DC
step down
regulator.
[0091] Referring to FIG. 10, the work light 701 can have the
electrical circuit shown with
socket 720a connected to charging circuit 1001. Charging circuit 1001 is
connected across battery
209 and the charging circuit is connected through switch 107 across LEDs 409
to both charge the
battery 209 and drive the LEDs 409 from the socket 720a and from the battery
209. A similar
electrical circuit can be used in other work light embodiments such as the
work light 100.
[0092] Charging circuit 1001 can be provided on driving circuit layer
408 of LED circuit
board assembly 211 can recharge batteries 209 while the LED work light 701 is
in use while
tethered. For example, the charging circuit 1001 may supply more current to
the batteries 209 than
the LEDs 409 draw from the batteries 209.
[0093] Charging circuit 1001 may, for example, include an application
of Linear Technology
Corporation of Milpitas, California (www.linear.com) LTC4002 standalone
battery charger
integrated circuit, such as the application described with reference to FIG. 2
on page 14 of Linear
Technology Corporation datasheet for LTC4002
(http://cds.linear.com/docs/Datasheet/4002f.pdf)
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30200380_1INATDOCS
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showing a single cell li-ion battery charger. To achieve greater magnitude of
charging current for
larger batteries (such as four single cell batteries each having a capacity of
2.2 amphours for use in
driving three Luxeon Rebel LEDs 409 having a nominal power rating of three
watts and operating
at one watt each for eight to ten hours runtime between charges) than that
achieved by the
schematic shown in the above reference document, five components are changed.
The resistance of
the current sense resistor Rsense is decreased proportionately. The inductor
Li is changed to one
having proportionally lower inductance than the one shown in the reference
schematic, and
increased current rating so as to be able to pass the increased current. The
diodes D1 and D2 are
changed to ones suitable for increased current, such as Schottky diodes rated
for 2-3 amperes of
current. The MOSFET transistor M1 is changed from the one specified in the
reference document
to one that is suitable for increased charging current, such as Fairchild
NDT452AP or Zetex
ZXMP3A16GTA.
[0094] The switch 107 is shown as able to switch the LEDs 409 on and
off independently
of use of the charging circuit 1001. Also shown are resistors 1002 associated
with the LEDs 409
and limiting the amount of current drawn by the LEDs 409. Alternatively, an
LED driving circuit
may be used to control or regulate current flowing through the LEDs 409.
[0095] The thermal design of the LED work light 701, such as
appropriate heatsinking and
air mixing configurations, can be configured, for example employing the
techniques described
herein, to take into account any additional heat generation where LEDs 409 and
charging circuit
1001 are both functioning. The charging circuit 1001 can be operated
intermittently or at reduced
capacity to reduce heat generation. Preferably, the charging circuit 1001
supplies sufficient current
for the batteries 209 to gain charge or not lose charge while the charging
circuit 1001 and the
LEDs 409 are operated simultaneously. If desired, the charging circuit 1001
can be configured to
recharge the batteries 209 more rapidly when the LEDs 409 are not in use.
[0096] An LED work light 701 being usually connected to the cable 709 while
having
rechargeable batteries 209 reduces the chance of the batteries 209 being
completely discharged if the
LED work light body 707 is taken to a location where batteries 209 cannot be
recharged. If users of
LED work light 701 become accustomed to keeping the work light body 707
tethered to power cable
709 whenever possible, the users would be less likely to leave the LED work
light body 707 where
the LED work light body 707 would get lost, for example, where the LED work
light
17
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CA 2756472 2017-10-23
body 707 is used for doing work in a car that can be driven away while the LED
work light body
707 remains in the car.
[0097] Referring to FIG. 11, a work light 1300 can employ a cord reel
power cable assembly
1300a in place of the power cable assembly 708 and together with the work
light body 707. The
arrangement of the LED work light body 707 and cord reel power cable assembly
1300a comprising
cable 1301 coupled to work light body 707 via connector 1311, and cord reel
1302 having a
mounting bracket 1309 and a ball 1307 that can be slid along the cable 1301.
The mounting bracket
1309 can be attached to a wall, ceiling, trolley, cart or other equipment. The
ball 1307 fits
sufficiently tightly on the cable 1301 so that it can limit retraction of the
cable 1301 by the cord reel
1302. Limiting retraction of the cord 1301 by the cord reel 1302 can be
useful, so that the LED work
light body 707 is only retracted to a location that is reasonably clear of the
work area but still within
easy reach. The ball 1307 can be moved along the cable 1301 to adjust the
amount of retraction of
the cable 1301 when a user lets go of the LED work light body 707. A stop 1306
is provided to stop
the ball 1307 from being retracted into the reel 1302. The stop 1306 may
project from or be mounted
on the cord reel 1302, but may alternatively be a hole in the housing of the
cord reel 1302 that is
smaller in width than the ball 1307. The ball 1307 may be substituted with an
object of an alternative
shape, such as a cylinder or a cube.
[0098] A cord reel power cable assembly 1300a reduces the possibility
that the cable 1301
may come into contact with substances or objects that could damage the cable
1301. For example,
work lights are often used in locations that have chemicals on the floor or
moving objects, such as
cars, that could damage the cable 1301 over time. Additionally, an operable
tether, particularly a
manually operable tether, can allow for separate replacement or interchange of
eitherthe power
cable, cord reel, or work light body. This is particularly advantageous where
the cost of the separate
elements can be significant given the features discussed herein.
[0099] Dual mode tethering can be applied to battery operated LED work
lights which do
not utilize features of other embodiments described herein such as, for
example, inline battery
compartment and component chamber with overlapping LED circuit board assembly,
or, as a
further example, LED circuit board assembly heat sinking to a work light
housing. However, dual
mode tethering can provide synergistic benefits when applied in conjunction
with features of other
embodiments described herein such as, for example, inline battery compartment
and component
chamber with overlapping LED circuit board assembly, or, as a further example,
LED circuit board
assembly heat sinking to a work light housing. For example, other features
described herein can
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provide compact LED work lights, particularly together with dual mode
tethering, and such compact
LED work lights that can be costly benefit from tethering to reduce the
possibility of loss.
[00100] It will be understood by those skilled in the art that this
description is made with
reference to the preferred embodiment and that it is possible to make other
embodiments employing
the principles of the invention which fall within its spirit and scope as
defined by the following
claims. In particular and without limiting the above, persons skilled in the
art will recognize that
various features and functions of the different embodiments described herein
will be useful in other
embodiments, and that such features and functions may be used in such other
embodiments to create
new embodiments employing the principles of the invention.
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