U.S. patent number 3,643,089 [Application Number 04/841,715] was granted by the patent office on 1972-02-15 for lighting fixture for illuminating planar surfaces.
This patent grant is currently assigned to Century Lighting, Inc.. Invention is credited to Paul M. Marantz.
United States Patent |
3,643,089 |
Marantz |
February 15, 1972 |
LIGHTING FIXTURE FOR ILLUMINATING PLANAR SURFACES
Abstract
A lighting fixture for illuminating planar surfaces such as
walls or the like, is disclosed. The fixture comprises an
ellipsoidal primary reflector open at one end and on one side on a
plane generally parallel to its major axis, an elongated light
source at a focus of the primary reflector and extending along a
portion of the major axis thereof adjacent the focus, and a second
reflector juxtaposed to the open side of the primary reflector and
the light source.
Inventors: |
Marantz; Paul M. (New York,
NY) |
Assignee: |
Century Lighting, Inc.
(Clifton, NJ)
|
Family
ID: |
25285534 |
Appl.
No.: |
04/841,715 |
Filed: |
July 15, 1969 |
Current U.S.
Class: |
362/217.02;
362/346; 362/298; 362/217.14 |
Current CPC
Class: |
F21S
8/02 (20130101); F21V 21/04 (20130101); F21S
8/026 (20130101); F21V 7/09 (20130101); F21V
7/08 (20130101) |
Current International
Class: |
F21V
7/09 (20060101); F21V 7/08 (20060101); F21V
7/00 (20060101); F21S 8/02 (20060101); F21V
21/04 (20060101); F21V 21/02 (20060101); F21v
007/08 () |
Field of
Search: |
;240/41.1,41.3SC,41.3D,78CF,78H,103,104,105,25,78R,78HA,41.35R,41.35C
;350/292,294 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Queisser; Richard C.
Assistant Examiner: Snee, III; C. E.
Claims
I claim:
1. A lighting fixture for illuminating a planar surface, comprising
chassis means adapted to be operatively disposed in a surface
extending at right angles to the surface to be illuminated, a
reflector coupled to said chassis means and having an open end
thereof adapted to face the surface to be illuminated when the
fixture is operatively disposed, said reflector being an
ellipsoidal surface having a major axis thereof extending at an
oblique angle with respect to the surfaces to be illuminated when
the fixture is operatively disposed, said reflector being open
along a plane parallel to its major axis on its side closest the
surface to be illuminated when the fixture is operatively disposed,
and an elongated light source coupled to said chassis means and
disposed at the focus of said reflector, the light axis of said
source being coincident with the major axis of said reflector so
that light rays emanating from said light source in the direction
of said reflector are directed toward the surface to be
illuminated, and a concave specular member coupled to said chassis
means and having an open side and an open end, the open side having
edges thereof adapted to be positioned flush with the surface in
which the chassis means is disposed, and the open end thereof being
disposed adjacent said open end of said first-mentioned reflector
to define a light-emitting aperture.
2. A lighting fixture in accordance with claim 1, and a second
reflector coupled to said chassis means and juxtaposed to the open
side of said first-mentioned reflector so that rays emanating from
said light source in a direction away from said first-mentioned
reflector are returned to said first-mentioned reflector.
3. A lighting fixture in accordance with claim 1 wherein said
concave specular member is resiliently suspended from said chassis
means so that said member may be displaced for access to said
chassis means.
4. A lighting fixture in accordance with claim 3 wherein said
chassis means includes spaced upstanding brackets, said reflector
being coupled to said brackets, and spaced upwardly extending
spring members coupled to said chassis means and said concave
specular member being suspended from said spring members.
5. A lighting fixture for illuminating a flat planar surface
comprising a housing adapted to be recessed in a surface disposed
generally at right angles to the surface to be illuminated, a
curved reflector associated with said housing, an elongated light
source in said housing, a second reflector in said housing adjacent
said light source, said second reflector being an ellipsoidal
surface having a major axis thereof extending at an oblique angle
with respect to the surface to be illuminated when the fixture is
operatively disposed, the major axis of said second reflector being
generally parallel to the light axis of said source, said source
being disposed at a focus of said second reflector, said second
reflector being open at one side thereof to receive light rays
reflected from said curved reflector, said second reflector being
open at one end thereof remote from the light source so that light
rays received by said second reflector are reflected toward the
surface to be illuminated, and a concave specular member associated
with said housing and having an open side and an open end, the open
side having edges thereof adapted to be positioned flush with the
surface in which the housing is recessed, and the open end thereof
being disposed adjacent said open end of said second reflector to
define a light-emitting aperture.
6. A lighting fixture in accordance with claim 5 wherein the
surface of said second reflector extends, adjacent its open end,
beyond the intersection of a plane containing the minor axis of
said second reflector and the surface of said reflector.
7. A lighting fixture in accordance with claim 5, wherein said
housing and said concave specular member are coupled to a chassis
means.
8. A lighting fixture in accordance with claim 7 wherein said
concave specular member is resiliently suspended from said chassis
means so that said member may be displaced for access to said
chassis means.
Description
This invention relates to lighting fixtures for illuminating planar
surfaces, and more particularly, to recessed lighting fixtures
having minimum brightness at the aperture and capable of providing
a relatively even light distribution over a planar surface.
Lighting fixtures for illuminating planar surfaces, commonly
referred to as "wall washer" units, have heretofore been proposed.
Such units, when used to illuminate vertical walls, are generally
associated with the ceiling a short distance away from the wall.
Both surface-mounted and flush-mounted wall washers have heretofore
been provided. In many applications, the latter type is more
desirable, since its unobtrusive nature results in minimal
interference with room decor.
In creating a lighting unit, particularly of the flush-mounted
type, it is necessary to first consider, and to optimize if
possible, optical performance. Next, it is necessary to deal with
purely mechanical considerations; unit construction, installation,
and accessibility for service. A common shortcoming of known
flush-mounted wall washer units has been difficulty of access for
service, such as routine bulb replacement. It is most undesirable,
of course, to compromise performance for accessibility, but such
compromise has frequently been necessary in the past. Consequently,
it is an object of this invention to provide a flush-mounted wall
washer unit with optimum illuminating characteristics but ready
accessibility.
It is a primary object of this invention to provide a lighting
fixture with minimum brightness of the aperture.
It is another object of this invention to provide a lighting
fixture for illuminating flat planar surfaces, and having a minimal
number of parts.
It is yet another object to provide a lighting fixture suitable for
flush mounting and providing a neat external appearance.
Other objects will appear hereinafter.
The foregoing and other objects are achieved, in a presently
preferred form of the invention, by a fixture comprising a housing
adapted to be recessed in a surface disposed generally at right
angles to the surface to be illuminated; a primary reflector, open
at one end and one side, disposed in the housing; a light source
disposed in the housing at a focus of the primary reflector; and a
trim member yieldingly coupled to the housing. In such preferred
embodiment the trim portion is so disposed that its edges and the
peripheral edge of the primary reflector define the aperture
through which light emanates from the fixture. Also in such
preferred form, a portion of the interior of the housing provides a
secondary reflector, in juxtaposition to the primary reflector.
For the purpose of illustrating the invention, there is shown in
the drawings a form which is presently preferred; it being
understood, however, that this invention is not limited to the
precise arrangements and instrumentalities shown.
FIG. 1 is a side elevation view, in cross section, showing a
lighting fixture in accordance with the invention.
FIG. 2 is a bottom plan view of a fixture in accordance with the
invention, mounted in association with a supporting surface.
FIG. 3 is a partial cross-sectional view taken along the line 3--3
in FIG. 1.
FIG. 4 is a partial perspective view showing the association of the
primary reflector and trim portion of the present fixture.
Referring now to the drawings in detail, wherein like numerals
indicate like elements, there is seen in FIG. 1 a lighting fixture
designated generally by the reference numeral 10. The lighting
fixture 10 is mounted flush with a ceiling 12 at a position spaced
from a vertical wall 14 intersecting the ceiling 12.
Engaging the ceiling 12 is a plaster ring, designated generally by
the reference numeral 16. The plaster ring 16 includes a lower
portion 18 of generally circular cross section, and an enlarged
upper portion 20. A transition portion 22 joins the lower portion
18 and enlarged upper portion 20. Contacting the transition portion
22, in supporting relation to the plaster ring 16, is a mounting
pan 24. Brackets 26, 28 extend upwardly from opposite sides of the
mounting pan 24. Leveling clips 30, 32 are provided in association
with respective brackets 26, 28.
A chassis plate 34 is rotatably and removably coupled to the upper
portion 20 of the plaster ring 16. To effect such coupling, the
upper portion 20 of the plaster ring 16 is provided with a
peripheral groove 36. Peripherally spaced screws associated with
the chassis plate 34 cooperate with the groove 36 to retain the
chassis plate 34 in contact with the plaster ring 16. Only one
screw 38 is seen in FIG. 1. Others are provided, however, at
peripherally spaced points on the chassis plate 34. In the
illustrated embodiment, the thumbscrew 38 is in threaded engagement
with a downturned flange 40, offset at right angles to the chassis
plate 34.
A housing 42 is coupled to and supported by the chassis plate 34.
The housing 42 includes a part-cylindrical lower portion 44 and a
part-hemispherical upper portion 46. The interior of the housing 42
is preferably made highly reflective, for a purpose to be explained
later.
A peripheral flange 48 is provided in association with the lower
portion 44 of the housing 42. Thumbscrews 50, at spaced points
about the flange 48, removably couple the housing 42 to the chassis
plate 34.
Disposed within the housing 42 is a reflector 54. In the
illustrated embodiment, a bracket 56 is coupled to the reflector 54
and is adapted to support a socket 58. A light source 60,
associated with the socket 58, extends through an opening 62 into
the concavity of the reflector 54.
In the illustrated embodiment, the reflector 54 is coupled to
upstanding triangular brackets 64 coupled to the chassis plate 34.
Also, in the illustrated embodiment a conduit 66 disposed at an
upper portion of the housing 42 provides a means of entry for lead
wires 68 associated with the socket 58.
A trim member 70 is yieldingly coupled to the plaster ring 16.
Referring to FIGS. 2 and 4, the trim member 70 includes a concave
optical portion 72, juxtaposed to an open end of the reflector 54.
The concavity of the optical portion 72 is preferably coated with a
specular finish, such as a gloss black enamel. Associated with the
optical portion 72 is a skirt portion 74. The skirt portion 74 has
a plan shape corresponding generally to the shape of the lower
portion 18 of the plaster ring 16. Referring to FIGS. 1, 3 and 4,
the skirt portion 74 in the illustrated embodiment, includes an
upwardly extending annular flange 76. The annular flange 76, when
the trim member 70 is in its operative position, rests against an
inwardly extending shoulder 78 in the lower portion 18 of the
plaster ring 16, best seen in FIGS. 1 and 3. When in its operative
position, the trim member 70 is preferably flush with the surface
of the ceiling 12. This is perhaps best seen in FIG. 1. Thus, the
trim member 70 provides a neat unobtrusive external appearance for
the fixture 10. Indeed, when it is properly installed, little of
the fixture 10 is visible from the ceiling exterior other than the
trim member 70.
The illustrated form of the trim member 70 is intended for use in
conjunction with plaster ceilings. For ceiling of dry construction,
a variation of the trim member 70, not shown, may be provided
wherein the flange 74 extends horizontally past the edge of the
plaster ring 16.
The trim member 70 is maintained in its operative position by a
pair of torsion spring members 80. The spring members 80 pass
through slots 82 in a bracket 84, secured to the trim member 70 by
tabs 86 or the like. The spring members 80 also pass through slots
87 in the chassis plate 34. The spring members 80, therefore,
normally bias the trim member 70 to an operative position wherein
its annular flange 76 is seated against the shoulder 78. If access
to the interior of the fixture 10 is required, the trim member 70
can be withdrawn against the bias of the spring members 80 from the
lower portion 18 of the plaster ring 16. At such time, the light
source 60 and other internal components at the fixture 10 are
readily accessible.
Referring once again to FIG. 4, the reflector 54 is seen in
perspective. The reflector 54 includes laterally extending flanges
86 adapted for securement to the triangular brackets 64. Screws 90
or the like may be used to secure the flanges 88 to the brackets
64.
The shape of the reflector 54 is an important aspect of the present
invention. Such reflector 54 is a segment of an ellipsoid of
revolution. Referring to FIGS. 3 and 4, the reflector 54 is open at
one side and one end. In the illustrated embodiment, the edge 92
defining the open end lies in a plane intersecting the active
surface of the reflector 54 on an opposite side of the plane A-B of
the semiminor axis from the light source 60. In one operative form
of the invention, the plane of the edge 92 intersects the semiminor
axis A-B at an angle of about 50.degree.. The light source 60,
preferably a "tungsten-halogen" bulb, includes a linear
light-producing element 94, aligned with the major axis C-D of the
reflector 54. The light-producing element 94 of the source 60 is
thus coincident with the focus F of the reflector 54, and extends
along the major axis C-D on both sides of the focus F.
The major axis C-D of the reflector 54 extends generally
downwardly. Thus, in the illustrated embodiment, the axis C-D
extends downwardly at an angle of about 20.degree. to the vertical
and toward the wall 14.
The focus F of the reflector 54 is also the center of the
part-hemispherical upper portion 46 of the housing 42.
Referring to FIG. 1, a light ray X originating at the focus F and
impinging directly on the reflector 54 is reflected, due to the
ellipsoidal contour of the reflector 54 toward point F', the other
focus of the reflector 54. Another light ray, designated by the
letter Y, is shown originating at a point spaced from the focus F.
The light ray Y is directed at the hemispherical upper portion 46
of the housing 42, and is reflected therefrom back toward the
reflector 54. From the reflector 54, the light ray Y is reflected
toward the wall 14. Another light ray, designated by the letter Z,
is shown originating from a point close to the point of origin of
the light ray Y, but impinges directly upon the reflector 54. The
light ray Z is twice reflected from the surface of the reflector 54
and follows a path defining a greater angle with respect to the
plane of the wall 14 than the rays X and Y. Due to the elongation
of the light-producing element 94, the shape of the reflector 54,
and the juxtaposition of the part-hemispherical upper portion 46 of
the housing 42 to the reflector 54, the light pattern cast upon the
wall 14 by the fixture 10 is of even intensity over a relatively
large surface area. The surface of the reflector 54 is preferably
somewhat textured to "defocus" the rays, thereby eliminating
striations due to local variations in the light producing element
94.
The trim member 70 cuts off most rays emanating from the
light-producing element 94 but not directed or reflected toward the
wall 14.
The reflector 54 is conveniently formed from light-reflective sheet
material.
As has already been explained, the above-described construction
provides a readily accessible and easily serviced fixture. The
thumbscrews 50 provide for rapid assembly of the housing 42 to the
chassis plate 34. Also, the arrangement of the thumbscrews 38 and
peripheral groove 36 permits initial adjustment of the angular
disposition of the reflector 54 with respect to the plaster ring 16
and trim member 70.
The present invention may be embodied in other specific forms
without departing from the spirit or essential attributes
thereof.
* * * * *