TOWER LIGHT SHIELD

PROTECTEUR D'ECLAIRAGE POUR TOUR

English Abstract

The present invention relates to a beacon light shield or an obstruction light shield. The beacon or obstruction light shield includes a base for receiving the light fixture, a plurality of ribs mounted on the base, and concentrically rings mounted to the ribs. The concentric rings include an inner ring mounted at a first distance away from the center of the base and an outer ring mounted at a second distance away from the center of the base. The beacon or obstruction light shield masks light from the ground at both distances and at locations close to the tower, and does not interfere with the function of the required lighting for the aircraft.

French Abstract

La présente invention a trait à un pare-lumière de phare ou dobstacle. Le pare-lumière de phare ou dobstacle comprend une base pour recevoir le luminaire, une pluralité de nervures montées sur la base et des bagues concentriques montées sur les nervures. Les bagues concentriques comprennent une bague intérieure montée à une première distance par rapport au centre de la base et une bague extérieure montée à une deuxième distance par rapport au centre de la base. Le pare-lumière de phare ou dobstacle masque la lumière provenant du sol aux deux distances et à des emplacements situés près de la tour, et nentrave pas la fonction de léclairage nécessaire pour laéronef.

Claims

WHAT IS CLAIMED IS:
1. A tower light shield comprising:
a base for receiving a tower light,
a plurality of ribs mounted ort the base each extending horizontally from the
base, and
concentric rings mounted to the ribs, wherein the concentric rings include an
inner ring
mounted at a first distance away from the center of the base and an outer ring
mounted at a second
distance away from the center of the base,
where the inner ring and the outer ring each have a respective upper
peripheral edge that
defines a respective top horizontal plane, the top horizontal plane of the
inner ring being arranged
to be lower than the top horizontal plane of the outer ring.
2. The tower light shield according to claim 1, wherein the tower light is
a beacon.
3, The tower light shield according to claim 1, wherein the tower light is
an obstruction light.
4. The tower light shield according to claim 3, wherein the obstruction
light is dual
obstruction lighting (DOL).
5. The tower light shield according to claim 3, wherein the obstruction
light is single
obstruction lighting (SOL).
6. The tower light shield according to claim 1, wherein the inner ring
includes a sleeve for
shielding light reflecting off a tower leg.
7. The tower light shield according to claim 6, wherein the sleeve has an
upper peripheral
edge that defines a top horizontal plane which is higher than the top
horizontal plane of the inner
ring.
7

8. The tower light shield according to claim 6, wherein the sleeve is
mounted to the inner
ring.
9. The tower light shield according to claim 6, wherein a portion of the
inner ring is widened
to form the sleeve.
10, The tower light shield according to any one of claims 1 to 9, wherein
the concentric rings
are of a quasi-circular polygon shape.
8

Description

CA 02869091 2014-10-30
TOWER LIGHT SHIELD
FIELD OF INVENTION
[I] The present invention relates to a tower light shield or deflector, and
more particularly to
a tower light shield or deflector for use in connection with beacons or
obstruction lights.
BACKGROUND OF THE INVENTION
[2] Federal regulations require that obstructions to aircraft, such as
towers and the like be
fitted with elements to render them highly visible to approaching aircraft.
For this
purpose, lighting systems are deployed on structures above a certain height in
localities
where aircraft are present. A typical lighting system for such a purpose often
incorporates
a series of lights such as a beacon on top of the structure, and dual
obstruction lighting
(DOL) and/or single obstruction lighting (SOL) at designated heights, to
provide
sufficient light to be suitably visible to aircraft.
[3] With the use of such lighting systems, there have been growing concerns
of light
pollution to observers on the ground within the vicinity of a tower,
particularly at night.
This issue becomes more problematic as the number of towers increases in
residential or
cottage areas.
[4] Current solutions known in the field to control nuisance light from
tower obstruction
lighting includes use of light deflectors or optical stops to block or reduce
light in
undesired directions. By way of one example, an assembly shield has been
provided
including a number of frustoconically shaped elements stacked vertically where
each
frustoconically shaped element is spaced apart from an adjacent element to
provide
vertical spacing.
[5] Some problems with the conventional tower lighting solutions are that
they are prone to
collecting snow and ice, and thus impeding the light.
[6] There is therefore a need for an improved tower light shield or
deflector.
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CA 02869091 2014-10-30
SUMMARY OF THE INVENTION
[7] According to one embodiment of the present invention, there is provided
a beacon light
shield comprising a base for receiving a beacon light, a plurality of ribs
mounted on the
base, and concentric rings mounted to the ribs, wherein the concentric rings
include an
inner ring mounted at a first distance away from the center of the base and an
outer ring
mounted at a second distance away from the center of the base.
[8] According to another embodiment of the present invention, there is
provided an
obstruction light shield comprising a base for receiving an obstruction light,
a plurality of
ribs mounted on the base, and a plurality of rings mounted to the ribs,
wherein the
plurality of rings include an inner ring mounted at a first distance away from
the center of
the base and an outer ring mounted at a second distance away from the center
of the base.
BRIEF DESCRIPTION OF THE DRAWINGS
[9] These and other features of the invention will become more apparent
from the following
description in which reference is made to the appended drawings wherein:
[10] FIG. 1 is a perspective view of the tower light shield in accordance with
an embodiment
of the present invention.
[11] FIG. 2 is a sectional side view of the tower light shield of FIG. 1,
taken along X-X'.
[12] FIG. 3 is a top view of the tower light shield in accordance with an
embodiment of the
present invention, with an LED tower light installed in the center.
[13] FIG. 4 is a side elevation view of the tower light shield and the LED
tower light of FIG.
3.
[14] FIG. 5 is a perspective view of the tower light shield in accordance with
another
embodiment of the present invention.
[15] FIG. 6 is a top view of the tower light shield of FIG. 5.
[16] FIG. 7 is a side elevation view of the tower light shield of FIG. 5,
taken along Y-Y'.
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CA 02869091 2014-10-30
[17] FIG. 8 is a side elevation view of the tower light shield of FIG. 5,
taken along Z-Z'.
DETAILED DESCRIPTION
[18] Referring to the drawings, FIG. 1 shows a tower light shield or deflector
(also known as
collar) generally designated by reference character 10 according to one
embodiment of
the invention. The tower light shield 10 comprises a base 16 for receiving a
light fixture,
e.g., a beacon light, and a plurality of ribs 18 mounted to the base 16. The
tower light
shield 10 includes a plurality of concentrically arranged rings, in this
embodiment
including an inner ring 12 and an outer ring 14. The inner ring 12 is mounted
at a first
distance away from the center of the base 16 and the outer ring 14 is mounted
at a second
distance away from the center of the base 16. The inner ring 12 is adapted to
mask the
light for locations close to the tower, and the outer ring 14 is adapted to
mask the light for
locations at further distances. The tower light shield 10 can be used as a
light shield for a
beacon light at the top of a tower.
[19] In one embodiment as shown in FIG. 1, the base 16 is arranged at the
center of the
concentric rings 12, 14, and has an aperture 16a and a number of mounting
holes for
receiving the light fixture. The plurality of ribs 18 are mounted on the base
16, of which
four ribs are shown in the illustrated embodiment, which are designated by
reference
numerals 18a, 18b, 18c, and 18d. The ribs 18 are spaced apart from one another
and
extend radially from the base 16. The ribs 18 include mounting holes for
securing the
inner ring 12 and the outer ring 14 and may include flanges to increase the
rigidity of the
structure.
[20] In the illustrated embodiment of FIG. 1, the inner ring 12 and the outer
ring 14 may each
be constructed by a series of flat metal plates welded or otherwise assembled
together,
forming a quasi-circular polygon shape. The material and implementation of the
inner
ring 12 and the outer ring 14 is designed to take into consideration factors
such as
stiffness, durability against wind, weight, and/or desirable focal point. For
tower side
mounted beacons, the tower light shield 10 may further include a sleeve 20 at
the inner
ring 12. The sleeve 20 may project to a different height level compared to the
inner ring
12 and the outer ring 14. For tower side applications, the sleeve 20 is
adapted to shield or
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reduce light reflecting off a tower leg. The sleeve may not be necessary for
tower top
applications. In one embodiment, the sleeve 20 may be a separate piece mounted
to the
inner ring 12; and in an alternative embodiment, a portion of the inner ring
12 may be
widened to form the sleeve 20. In another alternative embodiment, one quarter
of the
outer ring 14 may be omitted which is shielded by the sleeve 20, which enables
the tower
light shield 10 to be brought closer to the tower leg.
[21] FIG. 2 provides a side sectional view of the embodiment as shown in FIG.
1. In
accordance with an exemplary embodiment, the inner ring 12 may have a diameter
of
about 2.6 inches and a height of about 5 inches; and the outer ring 14 may
have a
diameter of about 4 inches and a height of about 6.25 inches. The sleeve 20
for tower side
applications may be mounted between two adjacent ribs 17 and may expand less
than one
fourth of the inner ring 12. The sleeve 20 may have a height of about 7
inches.
[22] As best shown with reference to FIG. 2, each of the inner ring 12, the
outer ring 14, and
the sleeve 20 have a respective lower peripheral edge that defines a bottom
horizontal
plane and a respective upper peripheral edge that defines a top horizontal
plane. The top
horizontal plane of the inner ring 12 may be arranged to be lower than the top
horizontal
plane of the outer ring 14, as the inner ring 12 and the outer ring 14 are to
shield light of
different distances. In accordance with the exemplary embodiment, the top
horizontal
plane of the inner ring 12 may be arranged to be lower than the top horizontal
plane of
the outer ring 14 by a spacing of about 2 inches.
[23] The bottom horizontal planes of the base 16 and the outer ring 14 may
further be
arranged to substantially coincide with each other, and higher than the bottom
horizontal
plane of the inner ring 12. In accordance with one exemplary embodiment, the
bottom
horizontal plane of the inner ring 12 may be lower than the base 16 by a
spacing dl of
about 0.75 inch. The sleeve 20 may be mounted at a higher level compared to
the outer
ring 14 and the inner ring 12. For example, the top horizontal plane of the
sleeve 20 may
be higher than the top horizontal plane of the outer ring 14 by a spacing d2
of about 1.750
inches.
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[24] The heights and the spacing between the light fixture, the inner ring 12
and the outer 14
create a tiered structure effective in shielding light at different distances.
While specific
dimensions and configurations are given in the embodiment, it will be apparent
to a
person skilled in the art that other dimensions and configurations of the
inner ring 12 and
the outer ring 14 are possible, for example, depending on the manufacturer,
height and
configuration of the light fixture to be used as well as the distances from
the tower that
light is to be shielded toward the ground. Accordingly, the shapes and/or
widths of the
inner ring 12 and the outer ring 14 and their relative positions or relative
heights are
customizable depending on different applications. As well, while two rings 12
and 14 are
used in this embodiment, more than two rings may be used to implement the
tower light
shield.
[25] FIG. 3 provides a top view of the tower light shield 10, with an LED
tower light 22
installed in the center, in accordance with an embodiment of the invention. As
shown in
FIG. 4, the top horizontal plane of the LED tower light 22 is projected at a
higher level
than the horizontal plane of the outer ring 14 to ensure that the tower light
shield 10 does
not interfere with the function of the lighting required at the horizon.
Moreover, within
the coverage of a 360 azimuth around the tower, the tower light shield 10
masks the LED
tower light 22 below the horizon at distances and blocks the light from ground
view at
locations close to the tower. The tower light shield or deflector 10 according
to the
embodiment shields light toward the ground, but at the same time is able to
comply with
regulations and rules applicable for lighting required for aircraft.
[26] While the tower light shield 10 as illustrated in FIG. 1 can be used for
beacon lights at the
top of the tower, similar design can be adapted for use of obstruction lights,
for example,
for use of dual obstruction lighting (DOL) and/or single obstruction lighting
(SOL). The
DOL and SOL are typically lights employed midway at the tower or at the top of
a tower
that is below a certain height.
[27] FIG. 5 illustrates a modified tower light shield generally designated by
reference
character 30 according to another embodiment of the invention. The tower light
shield 30
is implemented for use of DOL and/or SOL. The configuration of the tower light
shield

30 is 24 inches and the diameter of the inner ring 32 is 18 inches. Similar to
the tower light
shield 10, the bottom horizontal plane of the outer ring 34 may be arranged to
be higher
than the bottom horizontal plane of the inner ring 32 by a spacing d3. For
tower side
mounted obstruction lighting, the tower light shield 30 may also include a
sleeve at the
inner ring 32. The sleeve may project to a different height level compared to
the inner ring
32 and the outer ring 34. The sleeve may not be necessary for tower top
applications. In an
alternative embodiment, one quarter of the outer ring 34 may be omitted which
is shielded
by the sleeve, which enables the tower light shield 30 to be brought closer to
the tower leg.
[28] While specific dimensions and configurations are given in the embodiment,
it will be
apparent to a person skilled in the art that other dimensions and
configurations of the inner
ring 32 and the outer ring 34 are possible, for example, depending on the
manufacturer,
height and configuration of the light fixture to be used as well as the
distances from the
tower that light is to be shielded toward the ground. Accordingly, the shapes
and/or widths
of the inner ring 32 and the outer ring 34 and their relative positions or
relative heights are
customizable depending on the applications. For example, while the tower light
shield 30
employs a round shape for the rings 32, 34, it will be understood to a person
skilled in the
art that other shapes, for example, an oval shield, may be used for the
obstruction lights.
As well, while two rings 32 and 34 are used in this embodiment, more than two
rings may
be used to implement the tower light shield.
[29] One or more currently preferred embodiments have been described by way of
example. It
will be apparent to persons skilled in the art that a number of variations and
modifications
can be made.
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Representative Drawing