U.S. patent number 3,571,585 [Application Number 04/774,938] was granted by the patent office on 1971-03-23 for panel and edge lighting assembly.
This patent grant is currently assigned to Coastal Dynamics Corporation. Invention is credited to Louis Clarence Schermerhorn.
United States Patent |
3,571,585 |
Schermerhorn |
March 23, 1971 |
PANEL AND EDGE LIGHTING ASSEMBLY
Abstract
An edge lighted panel for use principally in illuminating
nomenclature associated with aircraft instruments is provided with
front mounted lamps in substantially flush relationship with the
front surface of the panel and yet so designed that they may be
removed and replaced from the front surface. Electrical energy is
provided for the lamps by means of a printed circuit board affixed
to the rear of the panel and having conductive paths connecting to
leads associated with a filter housing for the lamp received in a
bore in the panel itself. The arrangement is such that replacement
of the lamps can be effected without having to disturb the panel,
filter housing and printed circuit board assembly.
Inventors: |
Schermerhorn; Louis Clarence
(Simi, CA) |
Assignee: |
Coastal Dynamics Corporation
(N/A)
|
Family
ID: |
25102764 |
Appl.
No.: |
04/774,938 |
Filed: |
November 12, 1968 |
Current U.S.
Class: |
362/631 |
Current CPC
Class: |
B60Q
3/14 (20170201); B60Q 3/64 (20170201) |
Current International
Class: |
B60Q
3/04 (20060101); B60Q 3/00 (20060101); B60q
003/04 () |
Field of
Search: |
;240/8.16,1 (EI)/ |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Matthews; Samuel S.
Assistant Examiner: Harris; Michael
Claims
I claim:
1. An edge lighted panel assembly comprising:
a. a panel having a bore passing from its front to rear
surface;
b. a printed circuit board having a printed circuit exposed on one
surface for carrying electrical power;
c. a filter assembly having electrical leads adjacent to the rear
surface of said panel when said assembly is positioned in said bore
such that when said printed circuit board is positioned against the
rear surface of said panel, said leads are in electrical engagement
with said printed circuit;
d. a cap and lamp assembly receivable in said filter assembly from
the front of said panel, said leads being electrically connected to
said lamp when received in said housing, said bore being
counterbored at its front end to define an annular recessed area
when said filter assembly is received in said bore; and,
e. an internally threaded ring member threadedly receivable on said
threaded end portion and dimensioned to seat in said annular
recessed area to thereby hold said filter assembly in said panel,
the top surface of said ring member and threaded end portion being
substantially flush with the front surface of said panel, and the
top of said cap and lamp assembly after being received in said
filter assembly being substantially flush with the front surface of
said panel,
whereby said cap and lamp assembly may be replaced from the front
of said panel without disturbing the assembly of said panel,
printed circuit board and filter assembly.
2. An assembly comprising, in combination:
a. a panel comprising a light conducting core in the form of a flat
sheet having a front viewing surface and a normally concealed rear
surface and including at least one bore of given diameter extending
normally entirely through said sheet, said bore being counterbored
on the front surface of said sheet to define an increased diameter
bore extending into said front surface of said panel a distance
less than the thickness of said panel to define an annular ledge
with said bore, said panel further including first and second
laterally extending channel segments on its rear surface
communicating with said bore;
b. a printed circuit board having on one surface a printed circuit
defined by at least first and second conducting paths spaced apart
by a distance such as to cross said first and second laterally
extending channel segments respectively when said surface of said
board is affixed in flush relationship to the rear surface of said
panel, said board including indexing cavities adjacent to said
conducting paths;
c. a filter assembly comprising a lamp housing having an externally
and internally threaded end portion defining an opening into said
housing; first and second conductors having lead portions extending
laterally from the other end portion of said housing opposite said
threaded end portion, one of said conductors electrically
connecting to said threaded end portion and the other terminating
in a central contact means in said housing, said housing including
small projections adjacent to said leads, the diameter of said
threaded end portion and housing being less than that of said bore
and the dimensioning of said conductors being such that said lead
portions are receivable in said channel segments respectively when
said housing and threaded end portion are passed through said bore
from the rear surface of said panel; an internally threaded ring
member dimensioned to be threadedly received on the externally
threaded part of said end portion and seat on said annular ledge in
said counterbore to thereby hold said filter assembly in said
panel, the top surface of said ring member and end of said threaded
end portion being substantially flush with said front surface of
said panel; and
d. a cap and lamp assembly adapted to be threaded into the
internally threaded part of said end portion of said lamp housing
such that the lamp portion of said assembly is within said housing
and the cap portion in electrical threaded engagement with said end
portion and flush therewith, the lamp in said assembly having a
filament with one end thereof electrically connected to said cap
and the other end positioned to be electrically connected to said
central contact means when said cap and lamp assembly is fully
threaded into said filter assembly, whereby said filter assembly
may be positioned on said printed circuit board with said small
projections received in said indexing cavities and with said leads
crossing said conductive paths and electrically connected thereto
so that electrical power may be applied to said leads from said
printed circuit board, and said panel may be positioned over said
printed circuit board with said filter assembly passing through
said bore, and said ring member thereafter threaded to said end
portion and finally said cap and lamp assembly threaded into said
filter assembly to provide a completed edge lighted panel assembly
wherein said cap and lamp assembly may be replaced from the front
surface of said panel and wherein there are no projections above
said front surface when said cap and lamp assembly is properly
threaded into said filter assembly.
3. An assembly according to claim 2, in which said cap includes a
transverse slot to receive a driver to enable threading and
unthreading of the same.
Description
This invention relates generally to edge lighted panel assemblies
and more particularly, to an assembly in which miniature lamps may
be mounted from the front of the panel and a printed circuit board
affixed to the rear of the panel for providing energy for the
lamps.
BACKGROUND OF THE INVENTION
Edge lighting of panels is well-known in the art and has wide
applicability, particularly in the illumination of instrument,
control, and console panels in aircraft. In such panels, light is
usually transmitted through the edge of a plastic or light
conducting core material. This material is provided with an opaque
surface coating except for transparent areas in the shape of letter
or numeral characters through which light is emitted. The letter or
numeral characters from the nomenclature identifies the control
positions of the switches, instruments, and other devices assembled
on the panel.
A desirable feature in edge lighted panels of the foregoing type is
to provide proper light sources and connections thereto distributed
in the panel in a manner which avoids projections on the panel
surfaces. In other words, a flush surface is desirable not only to
facilitate mounting the panel but to avoid interference with other
instruments which are inserted in the panel. In some panels
heretofore provided wherein a flush surface is realized, it has
been necessary to pot the entire lamp structures directly into the
panel itself. However, if a bulb or lamp should burn out, it is an
expensive and time-consuming operation to replace the lamp, such
operation usually requiring destroying part of the panel structure
itself as well as circuit connections to the lamp. As a
consequence, many more lamps than actually necessary for proper
lighting in such type panels have been required simply to meet
defined safety standards.
It will be evident that if a lamp structure could be designed for
easy removal and replacement without having to appreciably disturb
the remaining portions of the panel, lights could be immediately
replaced that are burnt out and thus the overall number of lights
presently required for safety purposes would not be necessary all
to the end that greater economy and ease of manufacture would be
realized.
In U.S. Pat. application Ser. No. 581,011, filed Sept. 21, 1966 and
assigned to the same assignee as the present application, there is
described a miniature light structure for an edge lighted panel so
designed that the light structure is flush with the surfaces of the
panel so that there are no projections from the panel. In addition,
the lamp structure is so designed that the lamp portion itself may
readily be removed and replaced without disturbing the remaining
portions of the panels or electrical power connections within the
panel.
The foregoing described miniature lamp structure includes a filter
assembly having electrical leads connected to buried conductors
within the interior of the panel itself. These leads and conductors
are potted within the panel and thus the filter assembly becomes a
permanent part of the panel. The provision of routed channels in
the rear of the panel for receiving power conductors, the
connection of these power conductors to the leads of the filter
assembly, and the subsequent potting of the entire structure is a
time-consuming operation in the manufacture of such panels.
Further, there is no ready means of gaining access to the filter
assembly itself without destroying the panel and buried conductor
connections therein. Thus, while the provision of a panel with
readily replaceable lamps is realized by the foregoing described
invention in the mentioned pending patent application, there still
result certain manufacturing difficulties as noted.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
With the foregoing considerations in mind, the present invention
contemplates the provision of an edge lighted panel assembly
wherein all of the advantages of the miniature light structure
described in the aforementioned pending patent application are
realized and yet wherein the panel assembly may readily be
disassembled to expose the filter assembly portion of the lamp
structure and corresponding electrical connections to power
leads.
In accord with the present invention, rather than utilize buried
power conductors within the panel itself, there is provided a
printed circuit board in combination with the panel. The printed
circuit board includes conducting paths exposed in a surface
thereof which surface is adapted to be placed in flush face-to-face
contact with the rear of the panel. The panel itself includes a
plurality of bores for receiving filter assemblies of miniature
lamp structures of the type described in the referred to copending
application. Towards this end, the panel itself may be provided
with channel segments on its rear surface for accommodating
laterally extending leads from the filter housing of the lamp
structure. An end portion of the filter housing in turn is modified
from the structure described in the referred to copending
application to include an end portion having both exterior and
interior threads. Cooperating with this filter housing is an
internally threaded ring member arranged to be threaded to the
exterior threads of the end portion of the housing and to seat in a
counterbored portion on the front face of the panel. The
arrangement is such that the filter housing with associated
electrical leads may first be secured to the printed circuit board
with the leads in electrical contact with conductive paths of the
printed circuit. The panel may then be placed over the filter
assembly and the internally threaded ring member then threaded onto
the end portion of the filter assembly from the front of the panel
thereby holding the printed circuit board, filter housing or
assembly, and panel itself together as a composite structure.
Thereafter, a cap and lamp assembly may readily be secured into the
filter housing from the front of the panel all in flush
relationship with the front surface as fully described in the
referred to copending application.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention will be had by now
referring to a preferred embodiment thereof as illustrated in the
accompanying drawings, in which:
FIG. 1 is a fragmentary exploded perspective view of a portion of a
panel and associated printed circuit board, filter assembly, and
cap and lamp assembly forming the basic components of the present
invention; and,
FIG. 2 is an enlarged cross section of the elements of FIG. 1 in
assembled relationship.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1 there is illustrated a portion of an edge
lighted panel including a light conducting core 10 preferably in
the form of a flat sheet of acrylic material having the property of
conducting light. The upper surface of the core 10 is first covered
with a translucent white substance such as a paint 11 and
thereafter with an opaque coating 12. Suitable letters or numeral
characters 13 forming desired nomenclature are defined by omitting
portions of the opaque coating 12 or removing given portions in the
shape of the desired legend to expose the white translucent
underpaint.
Distributed throughout the panel are a plurality of bores passing
entirely through the panel for receiving suitable light sources
generating light which is transmitted by the light conducting
properties of the panel core to illuminate the legends such as the
characters 13. One of these bores is indicated at 14 and in accord
with features of the present invention, includes a counterbored
portion 15 on the front surface of the panel defining a recessed
area terminating in an annular ledge 16. The rear side of the panel
includes channel segments 14a and 14b communicating with the rear
exit portion of the bore 14.
A printed circuit board 17 includes first and second conducting
paths indicated at 18 and 19. These paths connect with other
conducting paths such as 20 and 21 which further paths eventually
connect to suitable power input terminal points such as indicated
at 22 for the path 20. At certain positions adjacent to the
conducting paths, there are provided indexing cavities 23 and 24
for receiving suitable indexing projections on a filter assembly
constituting part of the miniature lamp structure.
As shown in FIG. 1, this filter assembly includes a filter housing
25 having laterally extending first and second electrical lead
portions 26 and 27. The positions of these leads are such that the
same will overlie the conducting paths 18 and 19 respectively when
the structure is assembled so as to effect an electrical connection
between the paths and leads.
As shown in FIG. 1, the filter housing 25 also includes an
externally and internally threaded end portion 28 defining an
opening into the housing. The dimensioning is such that the filter
housing structure can be received in the bore 14 when the panel 10
is lowered over the structure with the threaded end portion 28
extending into the recessed area above the ledge 16. In this
assembled state, the leads 26 and 27 fit within the channel
segments 14a and 14b on the underside of the panel.
Shown above the panel 10 is a ring member 29 having internal
threads 30. This member is arranged to be threadedly received on
the threaded end portion 28 of the filter assembly and to seat on
the ledge 16, the top surface of the ring together with the
threaded end of the filter housing all being flush with the front
surface of the panel.
The edge lighted panel structure is completed by insertion of a cap
and lamp assembly designated generally by the numeral 31. This
assembly includes a threaded cap 32 arranged to be threadedly
received with the internal threads of the end portion 28 of the
filter housing. A conducting collar 33 and lamp bulb 34 complete
this assembly. The top surface of the cap 32 is provided with a
transverse slot 35 for receiving a driver to enable threading and
unthreading of the cap and lamp assembly from the filter housing.
By this arrangement, the top surface of the cap and lamp assembly
will be flush with the front face of the panel when in assembled
relationship.
Referring now to FIG. 2, further details of the cap and lamp
assembly will be evident. As shown, the filter housing includes a
light transmitting filter material 36 surrounding the bulb 34 when
the cap and lamp assembly is threaded into the housing. Part of the
filter may terminate in projections 37 and 38 which are received in
the indexing cavities 23 and 24 respectively in the printed circuit
board 17. By this arrangement, the rotative position of the filter
housing is such that the electrical lead portions 26 and 27 will
properly electrically engage the conductive paths 18 and 19
respectively on the printed circuit board 17 when the same is
positioned with its surface in flush engagement with the rear
surface of the panel 10.
The lead portion 26 as is clear from FIG. 2 terminates within the
filter housing in a central contact 39, preferably in the form of a
ring contact through which the bulb 34 extends. The other
electrical lead 27 in turn connects directly to the threaded end
portion 28 to thus be in electrical engagement through the internal
threaded connection 40 with the cap 32.
The conducting collar 33 described in FIG. 1 is shown in FIG. 2 in
electrical engagement with the central contact means 39 when the
cap and lamp assembly is threaded into the filter housing. This
conducting collar 33 is electrically insulated from the cap 32 by
an insulating disc 41 and by a suitable insulating retaining collar
42. The disc 41 includes an opening through which one end of a
filament lead for the lamp 34 extends to engage in electrical
connection the cap 32 as at 43. The other end of the filament of
the lamp 34 connects directly to the collar 33 as at 44.
From the foregoing description, it will be evident that when the
cap 32 is threaded into the threaded end portion of the housing
assembly, electrical connection is effected between the leads 26
and 27 to the lamp filament. In this respect, the central contact
ring 39 is normally biased upwardly slightly such that when the
collar 33 is moved down against the contact 39, this contact will
move into a horizontal plane to thereby provide a reliable
connection. The other connection is assured through the threading
of the cap 32 as at 40 with the threaded end portion 28.
OPERATION
The operation of the edge lighted panel assembly will be evident
from the foregoing description. Preferably, the structure is
assembled by first locating various filter housing structures such
as the structure 25 of FIG. 1 on the printed circuit board 17.
These housings are properly located by means of the projections 37
and 38 described in FIG. 2 and the corresponding indexing cavities
23 and 24 on the board surface. With the various housings properly
assembled on the board 17, the leads such as 26 and 27 are soldered
directly to the conducting paths of the printed circuit.
Thereafter, the panel 10 with suitable bores such as the bore 14
being formed therein at corresponding locations to the housings on
the printed circuit board is simply lowered over the filter housing
structures to engage the surface of the printed circuit board in
flush relationship. Various ring members such as the internally
threaded ring member 29 are then threaded onto the upper protruding
end portions of the housing assemblies thus locking the housing
assemblies to the panel 10. Finally, the cap and lamp assemblies
such as 31 of FIG. 1 may be threaded into the filter housings.
If electrical power is now applied to the conducting paths of the
printed circuit board, it will be evident that the various lamps
will all be energized in the panel and thus suitable nomenclature
and the like will be clearly visible.
Should one of the lamps burn out, it is a very simple matter to
unthread the cap and lamp assembly 31 from the filter housing
without disturbing the relationship of the filter housing with the
panel and printed circuit board. Further, this change of the cap
and lamp assembly can readily be effected from the front surface of
the panel so that dismounting of the panel is totally
unnecessary.
In the event it should be desired to gain access to the filter
housing itself, the panel 10 may readily be separated from the
filter housing and printed circuit board by simply removing the
various ring members 29 from the housing assemblies, access to
these ring members again being had from the front of the panel.
With the ring members removed, the entire panel may then simply be
lifted off of the printed circuit board to leave the filter
housings all exposed.
From the foregoing description, it will thus be evident that the
present invention has provided an improved edge lighted panel
assembly wherein both front and rear surfaces are free of any
projections and yet manufacture and assembly is enormously
simplified.
* * * * *