Note: Descriptions are shown in the official language in which they were submitted.
CA 02754628 2011-10-04
A LUMINAIRE ARRANGEMENT
TECHNICAL FIELD
The present invention relates to luminaires and, in particular, to luminaries
having a reflector
of adjustable focal length including two curved portions. Such a reflector is
described in
WO 96/37732 (which has the same inventor as the present application) and will
hereafter be
termed a doubly arched reflector.
The above described luminaire is normally sold in knockdown form and is
assembled by the
purchaser. Hitherto, this assembly process has been relatively time consuming
because of the
large number of bolts, nuts and like fasteners which must be assembled.
OBJECT OF THE INVENTION
The object of the present invention is to provide an arrangement whereby such
a luminaire can
be assembled in a more convenient fashion.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, there is disclosed
a tensioning
mechanism for the reflector of a doubly arched luminaire, said mechanism
comprising a
flexible, substantially inextensible filament having a bulbous protrusion
formed at each end
thereof, and at least one aperture formed in each opposite side of said
reflector, each said
aperture having a main opening leading into a smaller extension, each said
main opening being
dimensioned relative to said bulbous protrusions to permit same to pass
therethrough and each
said extension being dimensioned relative to said bulbous protrusions to
prevent same passing
therethrough.
In accordance with a second aspect of the present invention, there is
disclosed a locating
mechanism for a pair of reflector sheets from which the reflector of a doubly
arched luminaire
is assembled, said mechanism comprising at least one mushroom-shaped stud on
one of said
sheets and a corresponding keyhole shaped aperture on the other of said
sheets, said stud
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comprising a stalk and a cap and said aperture comprising a main opening and a
smaller
extension wherein each said stud and aperture are dimensioned so that said cap
can pass
through said main opening but not said extension and said stalk can be
retained in said
extension with a friction fit.
In accordance with a third aspect of the present invention, there is disclosed
a tensioning
mechanism for the reflector of a doubly arched luminaire, said mechanism
comprising an
aperture formed at one side of said reflector, a swing arm pivotally mounted
to the opposite
side of said reflector, said swing arm having at least one aperture therein,
and a malleable
elongate member having a length sufficient to extend from side to side of the
tensioned
reflector and being able to have each end thereof formed into hook means able
to engage said
apertures.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described with reference to
the drawings in
which:
FIG. 1 is an exploded perspective view of a prior art luminaire of the doubly
arched reflector
type,
FIG. 2 is an end elevation of the luminaire of the preferred embodiment,
FIG. 3 is a partial schematic exploded perspective view illustrating how two
sheets can be
brought together to form the reflector,
FIG. 4 is an enlarged fragmentary side elevational view of a portion of Fig.
3,
FIG. 5 is a partial perspective view showing the two sheets assembled to form
the reflector,
FIG. 6 is an exploded perspective view of the lamp socket mounting for the
luminaire,
FIG. 7 is a schematic perspective view showing a first form of reflector
tensioning
arrangement,
FIG. 8 is an enlarged fragmentary view of a portion of Fig. 7,
FIG. 9 is an enlarged fragmentary view of a portion of Fig. 7, and
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FIG. 10 is a schematic partial perspective view of a reflector tensioning
arrangement of a
second embodiment.
DETAILED DESCRIPTION
As seen in Fig. 1, the reflector 1 of the prior art is formed from two sheets
2 preferably of
resilient metal construction which are joined together about a spine 3 in the
manner of the
pages of a book. A tensioning device in the form of a chain 4 and hooks 5 is
used to provide
the desired adjustment of the focal length of the reflector 1.
The remaining components of the luminaire are essentially a lamp socket
mounting 12 which
supports the lamp socket 18 which in turn supports the lamp 20. If desired, a
heat shield 17
having perforations 30 can be provided.
It will be apparent to those skilled in the art that the means by which the
lamp socket mounting
12 is held in position are cumbersome and require considerable adjustment to
ensure that the
longitudinal axis of the lamp 20 is parallel to the longitudinal axis of the
reflector 1.
Furthermore, the chain 4 whilst being practical is a relatively expensive
method of ensuring
that the required tension in the reflector is achieved. In addition, because
of the tendency of
the chain 4 to collapse unless placed under tension, many purchasers find it
awkward to
interengage the hooks S and the links of chain 4.
Turning now to Figs 2-5, the luminaire 100 of the preferred embodiment is
illustrated having a
reflector 101 formed from two sheets 102 and 122 essentially as before with a
lamp socket
mounting 112 and a pair of tensioning filaments 104 (only one of which is
illustrated in Fig.
2). The sheets 102,122 are supplied in a compact knock down form stacked one
above the
other and are then joined together to form a spine 103.
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As seen in Figs. 3 and 4, the sheet 122 is provided with a pair of generally
mushroom shaped
lugs 107 which each have a central cylindrical stalk 108 and a substantially
flat cap 109.
Conversely, the reflector sheet 102 is provided with a pair of keyhole
apertures 127 each of
which has a central opening 128 and a narrow extension 129 extending
therefrom. The
extensions 129 are substantially parallel. In addition, the portions of the
sheets 102, 122 which
are joined together to form the spine 103 each include four holes 111.
In order to move from the unassembled position illustrated in Fig. 3 to the
assembled position
illustrated in Fig. 5, the caps 109 of the lugs 107 are passed through the
central openings 128
of the corresponding keyhole apertures 127. This generally locates the two
sheets 102,122 in
the correct orientation and configuration. Then the sheets 102,122 are moved
relative to each
other in the direction of the spine 103 so as to engage the stalks 108 with
the corresponding
extensions 129. This results in a friction fit between the lugs 107 and the
keyhole apertures
127. The friction fit may be between the stalk 108 and the extension 129, or
between the
underside of the caps 109 and the surface of the sheets 102,122, or both.
The end result is the configuration illustrated in Fig. 5 where the holes 111
in the two sheets
102,122 are aligned. This enables arcuate hanging supports 114 to be secured
to the reflector
101 by means of fasteners 115 as illustrated in Fig. 5.
Turning now to Fig. 6, the lamp socket mounting 112 will now be described. The
interconnection between the lamp socket mounting 112 and the reflector 101 is
effected by
means of a base 121 which has a V-shaped bight 122 which is shaped to mate
with the spine
103. The bight 122 and spine 103 are interconnected by any convenient
mechanism such as
self-tapping screws (not illustrated) passing through the openings 123 in the
bight 122.
Preferably such screws pass into one of the pair of holes 111 so that the lamp
socket mounting
112 is positioned at one end of the reflector 101. Alternatively, the mounting
112 can be
located intermediate the ends of the reflector 101.
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In addition, the base 121 has a pair of arms 124 each of which has a
longitudinally extending
slot 125.
Lamp socket 18 is conventional and is mounted to an L-shaped cover 132 which
closes a
rectangular housing 133 having a pair of protruding side walls 134. Each of
the side walls 134
has a curved slot 135 therethrough. Located within the housing 133 are
electrical connectors
and possible ancillary electrical equipment (all not illustrated). In
addition, the L-shaped cover
32 has a pair of slots 136 each of which is shaped to receive a corresponding
arm 124 of the
base 121.
In operation, the base 121 is first secured to the spine 103 of the reflector
101. Then the arms
124 are each passed through the corresponding slot 136 and a screw fastener
137 passed
through each of the slots 125 and 135. By sliding the housing 133 up and down
the arms 124,
the preferred distance between the longitudinal axis of the lamp to be engaged
with socket 18
and the spine 103 can be set. In addition, by movement of both side walls 134
simultaneously
in the same direction relative to the arms 124, the longitudinal axis of the
lamp socket 18 can
be inclined towards or away from the spine 103 as desired. Furthermore, should
the lamp
socket axis not be parallel to that of the spine 103, one of the side walls
134 can be pushed
forwardly slightly whilst the other of the side walls 134 can be pushed
rearwardly slightly,
thereby moving the axis of the lamp socket 18 to right or left. Once these
fine adjustments are
made, the screw fasteners 137 are made fast.
It will be appreciated by those skilled in the art that the above described
adjustment and
alignment of the lamp socket axis is able to be easily and conveniently
carried out by the end
user once the lamp has been installed so as to ensure that the reflector 101
operates to the
maximum of its designed potential. This is not easy to accomplish using the
threaded fastener
arrangement illustrated in Fig. 1.
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Turning now to Figs. 7-9, it will be apparent that the reflector 101 can be
brought into the
required shape and hence desired focus, by means of adjusting the two
filaments 104. As
shown in the enlarged fragmentary views of Fig. 8 and 9, in the embodiment of
Figs. 7-9 the
filament 104 has a bulbous protrusion 144 at each end. In addition, as seen in
Fig. 8, at the
exterior side of the sheet 102 is located a single keyhole aperture 147 having
a central opening
and a narrow extension. Preferably, the narrow extension of the keyhole
aperture 147 is
directed in the direction in which the filament 104 is intended to lie.
Similarly, as seen in Fig.
9, on the outer edge of the reflector sheet 122 is located a corresponding
keyhole aperture 247
again having a central opening and narrow extension. The narrow extension of
the aperture
247 again preferably points in the direction of the filament 104. In addition,
adjacent to the
keyhole aperture 247 are four additional keyhole apertures 347 each of which
has its narrow
extension oriented towards the keyhole aperture 247.
It will be apparent from Figs. 7-9 that the reflector 102 can be compressed so
as to increase the
degree of curvature of the double arch. One end of the filament 104 with its
bulbous protrusion
144 is passed through the central opening of the keyhole aperture 147.
Thereafter, the filament
104 is tensioned slightly so as to draw the filament 104 into the narrow
extension of aperture
147 and thereby engage the bulbous protrusion 144 with the narrow extension.
Similarly, on
the other side of the lamp and at the other end of the filament 104, the
corresponding bulbous
protrusion 144 and filament 104 are passed through the central opening of the
keyhole
aperture 247 and one of the apertures 347 in turn. Again, when the filament
104 is tensioned
by the natural resilience of the reflector 101, the bulbous protrusion 144
comes into
engagement with the narrow extension of the selected keyhole aperture 347.
Clearly, selecting a different aperture 347 enables the tension within the
filament 104 to be
adjusted. A similar arrangement is provided for the other filament 104 at the
other end of the
reflector 101. In this way the degree of curvature of the doubly arched
reflector 101 can be
easily and uniformly set.
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Turning now to Fig. 10, an alternative tensioning mechanism is illustrated
which takes the
form of a pivoted arm 151 which is connected by means of a rivet 152 to the
sheet 122. The
arm 151 is able to be pivoted in the direction of the arrow in Fig. 10 so as
to lie in the position
illustrated by dotted lines in Fig. 10 rather than in the extended position
illustrated by solid
lines in Fig. 10. The arm 151 is provided with a number of openings 156 whilst
the other
reflector sheet 102 is provided with a single opening 155. The filament 104 of
Figs. 7-9, which
is preferably a stainless steel stranded wire, is replaced by a mild steel
wire 53 which is
malleable so as to form a hook at each end thereof. By appropriately bending
the wire 153 and
engaging the hooks with the opening 155 and one of the openings 156, an
appropriate degree
of tension can be achieved for the reflector 101.
The foregoing describes only some embodiments of the present invention and
modifications,
obvious to those skilled in the art, can be made thereto without departing
from the scope of the
present invention.
The term "comprising" (and its grammatical variations) as used herein is used
in the inclusive
sense of "having" or "including" and not in the exclusive sense of "consisting
only of.
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