US2824954A - Instrument panel lighting - Google Patents

Description

Feb. 25, 1958 J, M ROPER 2,824,954

INSTRUMENT PANEL LIQHTING Filed June 28, 1954 'Y' l j I O 55 l+ "if "ff INVENTOR United States Patent INSTRUlVIENI' PANEL LIGHTING John M. Roper, Washington, D. C., assignor to Grimes Manufacturing Company, Urbana, Ohio, a corporation of Ohio Application June 28, 1954, Serial No. 439,796

9 Claims. (Cl. 24U-8.16)

This invention relates to instrument panels or dials and to means for illuminating them so that the indicia or legends carried thereon may be read at night or under other circumstances involving the absence of natural lighting.

More particularly, the invention has reference to the illumination of the indicia applied to or incorporated inY the panels by light transmitted through the material of which the panel is composed, and from a light source carried by the panel and located substantially in the planeV thereof, whereby the rays of light are transmitted edgewise of the body ofthe panel.

The general object of the invention is to provide a novel and improved system of illumination of the class described, which will enhance the efficiency of the panel lighting, increase the compactness of the instrument assembly, widen the versatility of location of the light sources, and generally improve the provisions for illumination of the dials, instrument and console panels, and otherrindicia bearing surfaces, such as those to be found in the cockpits of aircraft, on shipboard, or elsewhere.

Although the edge illumination of plastic panel lighting' systems has been in use for some time, diculty and inconvenience have been experienced in the matter of the awkward rearward projection from the panel of parts of the lighting installation and the interference of such projecting parts with the instruments or instrument casings disposed behind the panels.

It is well known that space in the cockpit of an aircraft is at a premium and the various instruments, housings, and panels must be crowded as close together as possible, and the various fastenings, electrical connections and accessories must occupy a minimum of space and not interfere with the compact assemblage of the controls. Heretofore, the manufacturers of control instruments for aircraft had to take into consideration in the planning of the instruments and their housings and casings, the accommodation of the rearwardly projecting parts of the superimposed instrument or console panel, and the instrument boxes and the panels had to be designed to intert and accommodate irregularities of construction of this nature. The present invention enables the manufacture of the console equipment and the manufacture of the plastic plate panel and the locating of the lighting fixtures therein to be planned independently, the one without reference to any possibility of conict with the other.

Another advantage afforded by the present invention is the more elcient Ventilating and cooling of the lamp which is the source of illumination within the panel, and the elimination of any metallic or other opaque parts surrounding the lamp within the contines of the boundary surfaces of the plastic light transmitting panel plate.

Another feature of the invention resides in the utilization of the covering cap of the lighting xture on the outer face of the panel as one of the ground connections, so that inadvertent short-circuits of the lighting system through switch handles or other equipment located near the lighting fixture, are obviated.

Other objects and features of novelty, including the installation and arrangement of circuit leads to the lighting fixtures, again avoiding projection from the rear face of the panel, will be apparent from the following specication when read in connection with the accompanying drawings in which certain embodiments of the invention are illustrated by way of example.

In the drawings:

Figure l is a view in front elevation of a portion of an illuminated instrument or console panel embodying the principles of the invention;

Figure 2 is a vertical sectional view taken on line 2-2 of Figure 1;

Figure 3 is a horizontal sectional view taken atright angles tothe section of Figure 2;

Figure 4 is a view in perspective of a shell forming one of the conductor elements of the lamp mounting; l

Figure 5 is a fragmentary sectional View taken on line 5 5 of Figure l, and showing the embedment of a conductor in the surface of the light conducting panel; and

Figure 6 is a fragmentary detail view in section similar to that of the lower central portion of Figure 2, but showing an alternative arrangement of the conductor terminal.

In Figure 1 of the drawings there is illustrated an exemplary arrangement of a small section of an instrument or console panel for an aircraft or the like.

This panel section is indicated generally by the reference numeral 10 and as in some conventional constructions, it is provided with cutouts 11 for the application of' standard securing or fastening elements which serve to attach the panel to an underlying supporting plate 12, por-V tions of which are shown within the confines of the cutouts 11. This plate 12 may in practice be the front plate of casings or housings for the instruments or equipment behind the lighting panel. In the particular suggestive embodiment shown in Figure 1, the portions 12 may be projecting flanges from an instrument box, the boundaries of which box are indicated by the broken lines 13.

However, the present invention in its general aspects is applicable to a wide variety of instrument and console installations, whether in the cockpit of an aircraft, on the bridge of a ship, or/in any other installation where excellent controlled lighting is needed. The novel arrangement is particularly useful in situations Where the lighting panel 10 is applied to the front wall 12 of the instrument box and in close contact therewith.

The particular panel used for illustrative purposes in the drawings is provided with three control knobs 15 with their associated markers or indicator lines 16 and printed legends 17. The markings 16 and the legends 17 are illuminated from within the panel 10 which is made of light conducting material which may be selected from well-known plastics or other materials having the property of conducting or transmitting light. The major portion of the surface of the panel where the markings and legends do not occur is coated with an opaque material preferably having a black surface.

As sources of illumination for transmitting light through the body of the panel 10 to the legends and markings which are to be illuminated, there are provided the lighting fixtures indicated generally by the reference characters 2l). These lighting fixtures are disposed at strategic points upon the panel so as to be uniformly distributed with respect to the legends to be illuminated. As these lights are so designed as to not project into the control box beyond the lighting panel, they can be located as desired without regard to the arrangement of equipment in the control box. The two lamp assemblies 26 shown in Figure 1 are symmetrically disposed with respect to the markings for the three switches 15.

The lamp installations 20 will now be described ,in

Patented Feb. 25, s

areV thus inconspicuous, avoid interference -with legends and instruments on the panel plate, and never enter the plate to any depth sufficient to interfere with the perfect transmission of light edgewise through the panel.

In the embodiment shown in Figure 2 of the drawings the wires are raised slightly from the surface of the plate 25 at the points where the lighting fixture 20 occurs and the finger terminals 5S and 60 are extended along the surface of the plate 25 and are wrapped around the raised portions of the wires which pass through grooves in the plastic rings 31. These grooves may be either pre-formed or the wires may again be used to embed themselves in the plastic by the use of heat.

In another embodiment of the invention as suggested in Figure 6, the surface of the plate 25 may be notched out and the ends of the prongs 55 and 60 projected into the notches and then bent around the conducting wires in their embedded position within the surface of the plate 25.

It Will be seen that by the provisions of this invention all projections from the rear face of the panel have been eliminated and thus the panel may be applied against the instrument casings without the necessity of indenting the casings or designing them to avoid the contacts which might project from the panel. There are also no metal portions of the lighting fixture projecting into the plastic plate 25 to interfere with the light distribution.

Various changes and modifications may be made in the embodiments illustrated and described herein without departing from the scope of the invention as dened by theV following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. An instrument console panel installation comprising, in combination, a panel plate composed of light transmitting material, opaque outer layers on both sides of said panel plate, apertures in the outer layer on the forward surface of said panel, said apertures defining indicia, an aperture in said panel plate, a cylindrical plastic bushing secured in said aperture and having an annular rib engaging one surface of said panel plate, a metal sleeve located within said bushing and having a nger terminal extending radially through said bushing between said rib and the surface of said plate, a lamp secured in said sleeve, said lamp comprising a bulb, a cylindrical cap which defines one electrical contact for said bulb and a central base contact extending from said cap, said metal sleeve defining another electrical contact for said bulb, a metallic shell engaging the portion of said bushing extending from said rib, said shell having a nger terminal thereon and having an internal annular groove interlocked with said rib, said shell being threaded on its outer periphery, and a plastic annular ring encircling said bushing in the region of the forward surface of said panel plate and engaging the f finger terminal of said metal sleeve and the finger terminal of said metal shell, said cap having an internally threaded tubular portion, said internally threaded tubular portion engaging the outer periphery of said metal shell, one of said outer layers extending around the outer periphery of said annular plastic ring, said tubular portion engaging said outer layer extension to provide a waterproof seal.

2. An instrument console panel installation in accordance with claim 1 wherein said body plate is coated on both sides with thin layers of translucent plastic and wherein a pair of conductors engage said finger terminals in the forward plane of said panel plate.

3. An instrument console panel installation in accordance with claim 2 wherein said conductors are imbedded in the forward surface of said panel plate and said finger terminals each extend around one of said conductors.

4. An instrument console panel installation comprising a panel pgate composed of light transmitting material, and having a rear surface adapted to come into close proximity totinstrumeuis or mechanisms to be controlled,

and a front surface bearing indicia adapted to serve asV reference media for controlling devices movably mounted adjacent said panel, said indicia adapted to be illuminated by light transmitted edgewise through the panel plate, a lighting fixture and conductors leading there.

from, said lighting fixtures and said conductors being carried by said panel plate and supported and positioned substantially forwardly Vof the plane of the extreme rear surface of said panel, said panel plate having an opening therein, said lighting fixture including a lamp, a base and socket assembly secured to the edges of said opening' with the lamp within the confines of the planes of the front andrear surfaces of said plate and the base and socket projecting forwardly of the plate, said socket having an annular projection thereon terminals extending from said assembly approximately at the plane of the forward surface of the plate, said conductors being connected to said terminals and disposed n substantially parallel and coplanar'relationship along the front surface of said plate, a covering and sealing ring surrounding the projecting portionsof said base and socket assembly, covering said terminals and conductor connections, and secured to said plate, the annular projection of said socket assembly being threaded and a threaded cap applied to said assembly and screwed down upon said sealing ring, and a coating'of covering material applied to the front surface of said panel plate, covering said conductors and said sealing coating, which ring is attached-to said ring about the margin of said opening and contacted by said threaded cap.

5. ln combination a translucent instrument panel having indicia thereon, an installation supported by and positioned substantially forwardy of the plane of the extreme rear surface of said panel, a miniature lamp including a bulb and a cylindrical base providing one electrical contact and an axially projecting post providing the other electrical contact, a metallic sleeve fitted closely about said base and having a terminal finger projecting radially therefrom at a point intermediate the ends of the lamp, a cylindrical tubular translucent member surrounding said sleeve and extending axially substantially the full length of the lamp and adapted to be fixed within an opening in the instrument panel, a metallic shell surrounding that portion of said cylindrical member which envelops the base of the lamp, the portion of the translucent cylindrical member which surrounds the bulb of the lamp being clear of any opaque envelopments, said outer shell being provided with a radially projecting terminal finger and being externally threaded, the first named terminal finger extending from the middle sleeve which surrounds the lamp base and projecting through the wall of the cylindrical translucent member, and a metal internally threaded cap screwed down upon said metal shell and having an electrical contact engaging said terminal post of the lamp whereby when said xture terminals are connected with a source of current, the current fiows from the first named finger through the metal sleeve, the cylindrical portion of the lamp base, the lamp filament, the contact post, the screw cap, the metal shell and the other terminal finger extending from said shell.

6. An instrument console panel installation in accordance with claim 5 wherein the terminal nger extending from the outer metallic shell is connected to ground so that the exposed metal screw cap is grounded Whereby the danger of short circuiting by inadvertent contact between other conductors and the cap is obviated.

7. An instrument console panel installation comprising a translucent supporting panel, opaque outer layers on both sides of said panel, a cylindrical tubular translucent member mounted in said panel, an externally threaded metallic shell surrounding said tubular member for approximately half its length from one end thereof having a finger terminal thereon, a metallic sleeve disposed

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