US 3097903 A
Abstract available in
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Description (OCR text may contain errors)
July 16, 1963 B. MOORE 3,097,903
LIGHT FIXTURE Filed June 2'7, 1960 50 e '/7'00/" 9 INVENTOR.
United States Patent 3,097,903 LIGHT FIXTURE Buell Moore, Houston, Tex., assignor to Esquire, Inc., a corporation of Delaware Filed June 27, 1960, Ser- No. 38,994 3 Claims. (Cl. 339-55) This invention relates in general to a light fixture. In one of its aspects, it relates to an improved fixture for electrically mounting a lamp within an enclosed case.
One filament type lamp, which is particularly well suited for use in a fioodlight or other fixture for reflecting a thin, wide beam of light, is known commercially as the Quartzline and is manufactured by the General Electric Company. Because of its small physical dimensions in comparison to other lamps having similar light producing capacities, this particular lamp may be mounted in a correspondingly smaller and therefore less expensive case. However, the heat produced within this lamp is so great that its envelope must be made of quartz rather than glass. The terminals of the filament which extend through the sealed ends of the envelope are made of molybdenum,
apparently because of its compatibility with quartz insofar as thermal expansion is concerned.
it is known, however, that molybdenum will oxidize at temperatures above 350 C. and, upon oxidation, will expand to break the seal with the quartz envelope. In open type light fixtures, this presents no particular problem because the surrounding atmosphere will normally dissipate enough of the heat from the lamp to prevent the terminals from being raised to the critical temperature. However, it has been found that, in the ordinary fixtures which are enclosed to protect against weathering and other damage, and which do not employ some sort of forced air ventilation, the terminals are heated up over the critical temperature, thereby destroying the seal. a Another characteristic of this particular lamp is that its envelope will darken unless it is mounted within 4 degrees of a horizontal plane. Furthermore, the configuration of this as well as other thin lamps having end terminals makes it impractical to replace other than through a. removable cover of the enclosed case. Normally, the window of the case through which the light is reflected is mounted within this cover to facilitate its replacement when broken, scratched or otherwise damaged. However, in prior cases of this type, the window has been detachably mounted on a frame of the cover by means of bolts, screws or other parts which require time consuming manipulation.
An object of this invention is to provide an enclosed light fixture for electrically mounting the aforementioned lamp or other lamps wherein the end terminals there-of must be kept below a critical temperature which would be otherwise exceeded if the lamp were to be mounted in a conventional fixture.
Another object is to provide a light fixture of the type above described having sockets of such construction as to quickly conduct the heat away from the terminals, particularly before they exceed this critical temperature.
A further object is to provide such a light fixture having sockets of the type above described which may be manufactured, assembled and replaced with a minimum of time and expense.
Yet another object is to provide a light fixture which enables the user to determine whether or not the lamp is disposed within a permitted limit of inclination.
Still another object is to provide an enclosed light fixture having a removable cover with a window mounted thereon for replacement with greater facility than heretofore possible.
A still further object is to provide a clip of simplified construction for so mounting the window or other part.
Other objects, advantages and features of this invention will be apparent to one skilled in the art upon a consideration of the written specification, the attached claims and the annexed drawing.
In the drawing, wherein like reference characters are used throughout to designate like parts:
FIG. 1 is a front elevational view of a light fixture constructed in accordance with the present invention;
FIG. 2 is a partial sectional view of the light fixture upon an enlarged scale and taken along section line 2-.--2 of FIG. 1;
FIG. 3 is a partial sectional view of one end of the fixture also upon an enlarged scale and taken along broken line 3--3 of FIG. 2, certain parts of one socket being shown in elevation; and
FIG. 4 is another partial sectional view of the light fixture, taken along broken line 44 of FIG. 1 and showing an edge of the removable cover of the case of the fixture.
Referring now particularly to FIG. 1, the light fixture, which is indicated in its entirety by reference character 10, comprises an enclosed case 11 mounted in an upright position upon a mast fitter 12 which is releasably fitted over the upper end of mast 13. A lamp 14 of a character to be described more fully hereinafter extends horizontally across the case and has its opposite ends electrically mounted within sockets 15- on opposite ends 16 of the case.
A depending arm 18 on the lower side of the case is pivotally connected by a pin 20 to the upper end 19 of the mast fitter 12 to permit the case 11 to be swung about a horizontal axis. Thus, the angular direction of the beam of light from the lamp 14 may be adjusted without, at the same time, disturbing the substantially horizontal disposition of the lamp which, as previously noted, is essential if the envelope is to remain clear.
The back 21 and opposite sides 16 of the case 11 merge to form a generally concave housing having its inner surface covered with a reflector 22 for reflecting a desired pattern of light from the lamp 14 through a glass window 23 on the front of the case. This window is mounted within a frame 24 to form a cover 25 which is releasably connected across the open front of the housing to enclose the case. More particularly, the cover and housing are provided with matching flanges having openings to receive wing nuts 25a or other releasable fastening means. As shown in FIG. 4, an O-ring 25b seals between the abutting faces of the housing and cover to render the case Weatherproof.
The lamp 14 comprises a tungsten filament 17 contained within a quartz envelope 26 which is long and thin in configuration. The opposite ends 27 of the envelope are pinched down (FIG. 2) to seal about a molybdenum wire 28 which is welded at its inner end to the filament 17. Each outer end of the wire is provided with a terminal 29 supported by a ceramic fitting 30 over the end of the envelope. It should be understood, of course, that the description of this lamp is merely for the purpose of illustrating the novel aspects of the light fixture 10, and that the construction. of such lamp does not comprise any part of the present invention.
Each socket 15 comprises a tube 31 tightly received within an opening 32 through each side 16 of the case. Thus, the inner diameter of each tube 31 provides an elongated opening 33 through one side of the case which is axially aligned with a similar opening through the other side thereof. A sleeve 34 of ceramic material such as porcelain, which is electrically insulating and heat conducting, is fitted closely throughout its length within the tube 15. A terminal 35 has a large body or plug which is fitted closely within the ceramic sleeve 34 and spaced from its inner end to provide a recess 36 therein for receiving the ceramic fitting 30 on the end of the lamp 14.
This terminal 35 has a protuberance 37 on the inner end of its enlarged body for contacting the terminal 29 mounted on this sleeve, and electrical conduits 38 extend from each terminal through the outer end of the opening 33 through the tube 31. The conduits 38 then extend through an opening 39 in the back 21 of the case for further extension (in a manner not shown) through the mast fitter for connection to a source of power. The exterior portion of the conduits are protected by a plate 42 which is bolted at 43 or otherwise removably secured to the end of the case 16 over each of the openings 32 and 39 therein.
As shown in FIG. 2, the inner end of each terminal body is upset at 43a for engagement by an inwardly facing annular shoulder 44 on the ceramic sleeve surrounding such terminal. Also, a thin sheath 40 of fiberglass or other electrical insulating material is passed over the outer end of each terminal body for extension outwardly therefrom about a portion of the inner end of the elec trical conduits 38. The inner end of this sheath is cemented to each of the terminal body and surrounding ceramic sleeve 34 at the annular intersection between the outer end of such sleeve and the terminal body. Thus, the electrode and ceramic sleeve of each socket will move inwardly and outwardly with one another within the opening 33 of the socket.
The ceramic sleeve and terminal of the left-hand socket 15 are releasably held against outward movement from the position shown in FIG. 2 by means of a small pin 45 which extends through the tube 31 for engagement with the outer end of the ceramic sleeve 34. As will be apparent from the drawing, inward movement of the ceramic sleeve and terminal is limited by the electrical conduits 38. The sleeve and terminal of the right-hand socket are also limited insofar as further inward movement is concerned by means of the electrical conduits 38. However, these parts of the right-hand socket are yieldably urged inwardly by means of a coil spring 41 which is compressed between the outer end of the sleeve 34 and the inner side of the plate 42 covering the outer end of the right-hand socket.
More particularly, the spring 41 is yieldable to permit the terminal 35 of the right-hand socket to be moved outwardly from the position shown in FIG. 2 a distance sufiicient to bring the lamp 14 into alignment with the recesses 36 in the sockets. That is, upon assembly of the lamp within this fixture, the right end thereof is first pressed against the spring-pressed terminal of the righthand socket so as to enable its left end to be moved past the inwardly extending portion of the tube 31 and into a postion opposite the recess 36 in the left-hand socket. Then, the left-hand end of the lamp may be eased into its recess 36 until its terminal 29 engages with the protuberance 37 of the terminal of the left-hand socket, at which time the lamp may be released to permit the compressed spring 41 to further expand in equalizing the force with which the terminals engage one another on opposite sides of the lamp.
Obviously, the lamp 14 is removed from mounted position by a reversal of this procedure. That is, the lamp is first moved to the right so as to compress the spring 41 an amount sufiicient to permit the left end of the lamp to be removed from its recess, at which time the lamp may be moved longitudinally to the left to remove its right end from the recess 36 of its socket. It is further obvious that, if desired, the terminal of both sockets may be urged inwardly to yieldably engage the terminals 29 on opposite ends of the lamp.
The ceramic sleeve and terminal of each socket, as Well as the spring 41 of the right-hand socket, are removable from and insertable into the outer end of the opening 33 of each socket. Obviously, in the case of the left-hand 4 socket, this removal and insertion requires manipulation of the pin 45 which, as shown in FIGS. 1 and 2, is accessible through the front side of the case.
Preferably, the housing of the case 11 is an integral casting of aluminum, although it may be formed of separate parts of aluminum or other suitable material. Although the opening 33 in each end of the case is, in the illustrated embodiment, provided by a separate tube 31 of aluminum or other metal, it may be provided by a tubular portion cast integrally with the ends of the housing. As previously mentioned, the sleeve 34 is of a suitable ceramic material, such as porcelain, which conducts heat, but insulates against the passage of electricity. As is conventional, the terminal 35 is formed of a metal such as copper.
The above-described socket 15 will quickly conduct the heat in the lamp 14 away from the molybdenum wires 28 to prevent the latter from reaching a temperature which would otherwise break the seal of the end 27 of the envelope about it. Thus, the large body of the terminal 35 provides a rapid path of heat conduction from the terminal 29 through the protuberance 37'. Also, as previously noted, this large body of metal is closely received within the ceramic sleeve 34, thereby providing a large annular area for heat conduction from the terminal to the sleeve 34-. Still further, and again as previously noted, the sleeve 34 extends closely within the metal tube 31, thereby providing another large annular area by means of which the heat may be conducted from the sleeve 34 to the metal tube 31, and thence to the large body of metal provided by the end of the case 16. This heat in the sleeve 34 not only results from the heat conducted to it by the large body of terminal 35, but also by virtue of heat conduction from the end of the lamp :14 which is received within the recess 36. Thus, in summary, this socket provides three distinct paths of heat conduction away from the end of the lamp which surrounds the molybdenum wire 28.
The position of the lamp 14 with respect to a horizontal plane is determined by means of a pendulum 46 which is suspended from its upper end by a pin 47 attached to the front of the mast fitter 12 for free swinging about a horizontal axis extending transversely of the lamp. As shown in FIG. 1, the lower end of this pendulum is marked with an O for alignment with a datum point 48 on the mast fitter 12 to indicate a vertical position of the pendulum 46, and thus a horizontal position of the lamp 14. Additional markings on opposite sides of the 0 indicate the limits of angular disposition of the lamp with respect to the horizontal whereby the user of the lamp may, at any time, determine if the lamp is within such limits. As noted in FIG. 1, the mast fitter is releasably connected to the upper end of the mast 13 by means of a set screw 49 or the like so that the entire fixture 10 may be mounted upon different masts.
As previously described, it is ordinarily more practical to replace a lamp of this configuration through a removable cover 25, rather than through the end sockets. As distinguished from previous covers for fixtures of this type, the glass window 23 is releasably fastened to the frame 24 by clips 50 of a construction which greatly facilitate the replacement of the window. As shown in FIG. 4, the inner side of the frame 24 is provided with a recess 51 thereabout upon which the rim of the window 23 rests with its outer edges 52 spaced therefrom. Preferably, a cushioning material 53 is disposed between the rim of the window and the recess.
Each clip 50 comprises a narrow strip of spring metal which is bent at 54 to provide a first longitudinally extending portion 55 and a second such portion 56. The first portion extends along the outside of the frame and has its outer end bent inwardly to provide a fastening flange 57 for snapping over the outer edge of the frame. More particularly, this flange fits within a depression 58 on the outer edge of the face of the frame 24- which is of a width to closely receive the opposite sides of the flange and hold it against any substantial lateral movement.
The second longitudinally extending portion '56 of the clip extends over the inner sides of the frame to a U- shaped section 59 which is intermediate the bend 54 and a fastening flange 60 on its outer end. The flange is disposed over the inside rim of the Window 23 to hold it against the cushion 53, while the U-sh-aped section extends into the space between the edge 52 of the window 23 and the inner side of the recess 51 to cushion the window about its edges.
It is obvious that the clip 50 is assembled to fasten the window 23 to the frame 24 by disposing the flange 60 over the window with the U-shaped section 59 in position between the window edges 52 and the inner side of the recess 51, whereby the flange 57 of the longitudinally extending portion 55 simply snaps into the recess '58. The clip is quickly and easily removed from attaching position by a reversal of this procedure.
From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be uunderstood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.
The invention having been described, what is claimed is:
1. A light fixture, comprising an enclosed metal case having spaced-apart sockets in the end walls thereof to electric-ally mount a lamp therebetween, each socket comprising means on the end wall of the case providing an elongated cylindrical opening which extends inwardly from the outer side to the inner side of said end wall, a ceramic sleeve disposed within and having an outer cylindrical surface contacting along said opening, a terminal received within the sleeve in contacting relation thereto and spaced from the inner end thereof to provide a recess within the sleeve for receiving an end of the lamp, spring means for urging the terminals within said sleeves into engagement with the terminals on the ends of the lamps when said ends are received within said recesses and being yieldable to permit first one and then the other lamp end to be inserted within or relieved from its recess, and a cover removably attached to the outer side of the end wall of the housing to enclose the outer end of each socket, the thickness of each end wall from its inner to its outer side and the longitudinal extent of the contact between the sleeve and socket opening extending through said end wall each being relatively large with respect to the diameter of said opening.
2. A light fixture of the character defined in claim 1, wherein the diameter of the outer end of each socket opening is at least as large as the diameter of the ceramic sleeve received therein, and said spring means is compressed between the end of the ceramic sleeve and the inner side of the cover, whereby the spring means, sleeve, and terminal of each socket may be moved outwardly through said opening upon removal of the cover.
3. A light fixture of the character defined in claim 1, including means providing another opening extending inwardly from the outer side of each end wall of the case, and an electrical conduit extending from the terminal of each socket through the socket opening, over the outer side of said end wall, and back into said other opening, said cover also enclosing said other opening and the portion of said conduit extending over the outer side of the end wall.
References Cited in the file of this patent UNITED STATES PATENTS 778,756 Miller Dec. 27, 1904 1,533,975 Dene Apr. 14, 1925 1,708,068 Kuney Apr. 9, 1929 1,785,332 Thom Dec. 16; 1930 1,935,440 Found Nov. 14, 193 3 2,150,497 Fernberg Mar. '14, 1939 2,215,531 Pieper Sept. 24, 1940 2,393,616 De Reamer et a1 Jan. 29, 1946 2,642,632 Savage June 23, 1953 2,769,082 Steiner et a1. Oct. 30, 1956 2,997,574 Miskella Aug. 22, 1961 FOREIGN PATENTS 528,283 Great Britain Oct. '25, 1940