BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to multiple signal annunciators such as are used on the instrument panels of jet aircraft and space ships to monitor the functioning of their various control and operating systems and components. The lamp block of the present invention is the lighting and signalling component of these multiple signal annunciators.
2. Description of the Prior Art
The closest patents known to applicants are:
Name Number Date __________________________________________________________________________ Grimes 2,340,053 Jan. 25, 1944 Noyes 2,916,725 Dec. 18, 1959 Noyes 2,925,592 Feb. 16, 1960 Arrasmith 3,107,350 Oct. 15, 1963 Parsons 3,139,616 June 30, 1964 Harrington 3,241,136 Mar. 15, 1966 __________________________________________________________________________
SUMMARY OF THE INVENTION
The invention comprises a lamp block for multiple signal annunciators, said lamp block containing one or more lamps and having a color filter laminated thereto as one wall thereof, with indicia markings on said filter, made visible to the eye when the lamp or lamps are lit.
In one form of the invention, the lamp or lamps are permanently encased within the block. In another form of the invention, they are removable therefrom.
In either case, the same blocks may be used for different signals having different color requirements, by the simple expedient of laminating thereto appropriate color filters, e.g., color filters transmitting aviation yellow (amber), green, blue and red light.
Trunions are provided on the sides of the lamp blocks to enable them to pivot toward and away from a printed circuit through which they may be connected to the various operating and control systems which they are intended to monitor. Leaf spring contacts between the lamp blocks and the printed circuit serve to connect the lamps to the circuit and they also function as mechanical biasing means to pivot the lamp blocks into accessible positions away from the printed circuit for removal.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view of a lamp block made in accordance with one form of the invention, wherein the lamps are not removable.
FIG. 2 is a view of the back of the lamp block, showing its leaf spring contact members.
FIG. 3 is an inside view of the lamp block, looking in the direction of arrows 3--3 of FIG. 1.
FIG. 4 is a longitudinal section on the line 4--4 of FIG. 2.
FIG. 5 is a transverse section on the line 5--5 of FIG. 4.
FIG. 6 is a longitudinal section on the line 6--6 of FIG. 4.
FIG. 7 is a side view of a lamp block made in accordance with a second form of this invention, wherein the lamps are removable.
FIG. 8 is an end view of said lamp block.
FIG. 9 is a longitudinal section on the line 9--9 of FIG. 7.
FIG. 10 is a longitudinal section on the line 10--10 of FIG. 8.
FIG. 11 is a face view of a lamp block made in accordance with a third form of the invention.
FIG. 12 is a back view thereof, showing its leaf spring contact members.
FIG. 13 is a longitudinal section on the line 13--13 of FIG. 11.
FIG. 14 is an enlarged sectional view through the color filter component of the lamp block shown in FIGS. 11-13.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
Lamp block 10 made in accordance with the first form of this invention (FIGS. 1-6) comprises a housing 12, a base 14 providing a back wall for the casing, a color filter 16 providing a front wall for the casing, one or more miniature, high intensity lamps 18 within the casing, and a pair of contact members 20 serving as conductors between the lamps and the annunciator circuit. Such circuit is shown in the form of a printed circuit on the annunciator base in the drawing of our co-pending U.S. Pat. application Ser. No. 726,752, filed May 6, 1968.
The casing 12 is a plastic block (see FIG. 6) having one or more cylindrical chambers 22 formed therein to receive and accommodate the lamps. In the illustrated form of this embodiment of the invention, three chambers 22 are provided to accommodate three lamps. These lamps are connected in parallel to conductors 24 and 26 which support them on base 14. Conductors 24 and 26 are connected to spring contacts 20 through holes formed in the base and thereby connect the lamps to said contacts and to the circuits which the contacts engage.
Base 14 is also made of a plastic material and it is cemented or heat sealed to the back of casing 12, thereby closing the back of the casing and sealing it against moisture and foreign matter. Cemented or heat sealed to the front of the casing is color filter 16 which is also a plastic element. The color filter closes the front of the casing and seals it against moisture and foreign matter. The lamps and their conductors and all inner connections are thereby protected within the casing.
Illustrative of materials used for the plastic components of the lamp block (casing, base and color filter) are such thermoplastics as the polycarbonates (bisphenol-a) and the acrylic resins (methyl-methacrylates). Other thermoplastic compositions, as well as thermosetting resins may be used for the lamp block components. However, the color filter must, of course, be light transmitting, either transparent or translucent, and the preferred materials are Plexiglas of Rohm and Haas Company of Philadelphia, Pennsylvania (acrylate and methacrylate resin) and Lexan of General Electric Company of Schenectady, New York (polycarbonate).
The lamp block is coated on all sides with opaque material, except for its legend-marked portions which will shortly be discussed, to prevent the escape of light. In the preferred forms of this invention, this is effected by means of an undercoating 30 which is white and translucent and an outer coating 32 which is black and opaque. Other colors also may be used. Both coatings cover the entire block, the color filter, casing and base alike.
A suitable legend 34 may be inscribed upon the face of the color filter (as shown in FIGS. 11 and 14) and this may be done by various means and methods, e.g., mechanical engraving, chemical engraving or etching, and the like. These methods involve removal of the outer opaque coating in the legend areas, leaving the translucent undercoating intact. Other methods, e.g., silk-screening, may be used to coat the entire block with the outer opaque material except for the legend areas. This operation is conducted after the entire block is covered with the translucent undercoating. The areas that remain free of the outer opaque coating constitute the legend.
The result is a lamp block suited for use in multiple annunciators of the type shown in our said co-pending patent application Ser. No. 726,752, filed May 6, 1968. It may be used for any of the signalling purposes of annunciator systems, requiring only that appropriate color filters be utilized to provide the color signals desired, and that appropriate legends be applied. Trunions 36 pivotally support the lamp block in the annunciator.
Turning now to the second form of this invention as illustrated in FIGS. 7-10, it will be seen that lamp block 40 differs from lamp block 10 mainly in the fact that lamps 42 in lamp block 40 are removable and replaceable, while lamps 18 in lamp block 10 are not. Additionally, lamps 42 occupy the same chamber 44 while lamps 18 occupy separate chambers 22.
More specifically, lamp block 40 comprises a casing 46, a base plate 48 and a color filter 50, both adhesively secured or heat welded or otherwise joined to the casing to form a closed housing for the lamps. Open end holes 52 are formed in the end walls of casing 46 through which lamps 42 may be inserted into chamber 44. Sleeves 54 are fixed within said holes to serve as sockets for the lamp bases 56. Flanges 58 on said lamp bases abut sleeves 54 to limit inward movement of the lamps, while pivoted locking bars 60 on the end walls of the lamp block engage the lamp terminals and lock the lamps in place. To remove the lamps, said locking bars are swung away from the lamp terminals and the lamps are withdrawn from their respective sockets.
Locking bars 60 also serve as conductors connecting the lamp terminals to one spring contact member 62. Pins 64 and conductors 66 are included in the circuit. Conductors 68 connect the sleeves 54, and hence the lamp bases 56, to the other spring contact member 62. By this means, the lamps are connected in parallel to the printed circuit base of the annunciator, as illustrated in our co-pending patent application.
As in the case of the first lamp block above described, lamp block 40 is coated with an undercoating 70 which is translucent and an outercoating 72 which is opaque. A legend is applied to the color filter by the means and methods above described, e.g., by chemically or mechanically inscribing the legend in the outer coating covering the face of the color filter. Similarly, lamp block 40 is provided with trunions 74 on its side walls for pivotal mounting in the casing of a multiple compartmented annunciator as shown in our co-pending patent application.
Referring now to the third form of this invention (FIGS. 11-14), lamp block 80 resembles lamp block 40 in essential details, except that its lamps 82 are mounted on base plate 84 rather than on the end walls of the casing. As in lamp block 40, the lamps of lamp block 80 project into a single chamber 86. The bases of the lamps are set into receptacles 88 which are fixed in openings formed in the base. A single locking bar 90, swivelly mounted on the base by means of a centrally disposed pin 92, locks the lamps in place. To remove and replace the lamps, the locking bar is pivoted out of engagement with the lamps and the lamps may then readily be removed from their respective receptacles.
It will be noted in FIGS. 12 and 13 that the locking bar also serves as a conductor, being in contact with the lamp terminals and being connected to spring contact 94 by means of conductor 96. The lamp sockets are connected to the other spring contact 98 by means of receptacles 88 and conductors 100 and 102. The lamps are accordingly connected in parallel to the printed circuit which the spring contacts engage, as shown in our co-pending patent application.
Lamp block 80, like lamp blocks 10 and 40, is provided with a casing, a base and a color filter. Casing 104 is mounted on and secured to base 106, and the color filter 108 is mounted on and secured to the casing. In lamp block 80, the base may be made of an opaque, thermosetting plastic, such as Bakelite, a phenolformaldehyde resin made by the Bakelite Company, a division of Union Carbide and Carbon Corporation of New York, New York. Since this base does not transmit light, there is no need to coat it with an opaque coating. Consequently, the two coatings above mentioned, a translucent undercoating 30 and an opaque outer coating 32 need be applied only to the casing and color filter. As previously described, mechanical or chemical means may be used to remove portions of the outer coating to expose the translucent undercoating and thereby form a legend 34.
When used in an annunciator of the type shown in our co-pending patent application, lamp block 80 is pivotally mounted therein, and this may be done by means of trunions 110 formed on casing 104 and engaging bayonet slots in the walls of the annunciator.
The foregoing embodiments are intended to illustrate, not limit, the invention. These embodiments may be modified, and variations may be had, within the broad scope of the appended claims. For example, the undercoating (a translucent paint) is not an essential or critical element of the claimed combination. It is used to diffuse the light which passes through the color filter when the lamps are energized, and to blend the legend into the background when the lamps are not energized. The translucent undercoating may be omitted to permit unobstructed transmission of light through the legend areas of the color filter. Moreover, when the translucent undercoating is used, it need not coat the entire lamp block. Its function is performed only in the legend areas. A converse arrangement is also feasible, wherein the legend is coated with opaque paint and the areas surrounding the legend are free of opaque paint. Light would be transmitted through the surrounding areas and the legend would be made visible in profile in the form of dark lettering against a lighted background.