US2276842A - Mounting device for electric lamps - Google Patents

Description

March 17, 1942.

W. HARRlSON MOUNTING DEVICE FOR ELECTRIC LAMPS Filed Dec. 18, 1959 Fig.2

Inventor:

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a fllllllrllulum Harrison,

ar-d g /ww is Attorney Patented Mar. 17, 1942 MIOUNTING DEVICE FOR ELECTRiIC LAIVIPS Ward Harrison, Shaker-Heights, Ohio, assignor to General Electric Company, a

New York corporation of Application December 18, 1939, Serial No. 309,712

My invention relates in general to a mounting Claims.

arrangement for electric discharge devices such as the fluorescent lamp in commercial use at present. More particularly, my invention relates V to a mounting fixture for such discharge devices cealed from view and do not interfere with the free. and easy insertion of the discharge device in its holders.

and the auxiliary apparatus required tostart and operate the same.

Fluorescent lamps of the type in commercial useat present consist of a relatively long tubular envelope having a base at each end. The lamp is mounted between two sockets or holders which are secured to a suitable support preferably in the form of a fixture. The starting and operation of such fluorescent lamps requires, at present, a certain amount of auxiliary equipment, to

wit: a choke coil or ballast, an auxiliary or starter switch, and preferably, in addition; a small condenser across the said starter switch to prevent, among other things, radio interference and arcing at the switch points.

One form of starter switch which has recently come into use is a thermal switch of the.glow discharge type in which a glow discharge serves to actuate a bimetallic strip within the switch. The life of such a switch is naturally somewhat limited as compared to the life of the choke coil, and therefore the switch may have to be renewed in time. The same holds true for the condenser across the starter switch. It would be of con-' siderable advantage to mount the thermal switch and condenser within the lamp fixture so that they are readily accessible and can be quickly and easily replaced when necessary.

In certain types of fluorescent lamp installations, it is often desirable to mount the choke coil separately from the lamp fixture and at some distance therefrom in order to effectively reduce in the installation the sound of any hum produced by the choke coil. According to the invention, such an arrangement is possible with a minimum number (two) of circuit leads as compared to prior similar arrangements in which four such circuit leads were necessary, resulting in a complicated wiring system.

One object of my invention is to provide a mounting fixture for electric discharge devices and associated auxiliary apparatus which will permit easy replacement of the renewal parts of the auxiliary apparatus.

Another object of my invention is to provide a mounting fixture for electric discharge devices and associated auxiliary apparatus with thesaid auxiliaries so mounted in the fixture that, while they are readily accessible for quick replacement purposes, still they are substantially con- Still another object of my invention is to provide a mounting unit for electric discharge de-.

vices and associated auxiliary apparatus having separate sockets for the discharge device and for a replaceable circuit member such as a starter switch or condenser.

A further object of my invention is to provide a mounting arrangement for electric discharge .devices and associated auxiliary apparatus which will permit installation of the choke coil at a considerable distance from the fixture for the discharge device with the use of a minimum number of connecting circuit wires.

A feature of my inventionis the provision, in a fluorescent lamp fixture, of a socket for a combination starter switch and condenser unit, the socket being located within the fixture preferably between the two lamp holders mounted thereon and there' being an opening in the top wall of the fixture housing opposite the said switch socket to thereby permit insertion of the combinationstarter switch and condenser unit thereinto.

Further objects and advantages of my invention will appear from the following description of a species thereof and from the accompanying drawing in which: v Fig. 1 is a side view of a fixture comprising my invention showing the electric discharge device and auxiliary apparatus mounted in place thereon; Fig. 2 is a front view of the fixture shown in Fig. 1 but with one end only of the discharge device shown in place in its holder; Fig. 3 isa longitudinal sectional view of one end of the fixture comprising my invention with the discharge device, the holder therefor and the combination starter switch and condenser unit shown in elevation; and Fig. 4 is a diagrammatic illustration showing the manner in which the various auxiliaries shown in Figs. 1 to 3 are connected to the discharge device to form the starting and operating circuit therefor.

Referring to the drawing, the fixture according. to my invention comprises an elongated housing l0 consistingof a bottom wall l-l, side walls 52, and a removable top or cover plate 13. Opposi ely facing sockets or holders M are mounted at opposite ends of the housing ID, the said holders being similar to the holder disclosed and claimed in United States Reissue Patent No. 21,545, issued Aug. 27, 1940, to A. J. Marshaus. The holders N are so spaced as to permit the insertion therebetween of an electric discharge deviceli, such as a fluorescent lamp of the wellknown type in commercial use at present and comprising an elongated tubular envelope containing a thermionic electrode at each end, a

containing the lamp engaging contacts I8, ex-

tend through suitable openings in the cover plate l3. The said lamp engaging contacts are mounted in the inner opposing side faces IQ of said extensions It.

Secured to the base portion I! of one of the holders l4 and extending laterally from the holder away from the inner face l9 thereof towards the other holder I4 is a socket block or member of suitable insulating material, such as, for instance, Bakelite." This socket member is secured to the holder 14 by connecting screws 20' which thread into the connection terminals ll of the said holder. The holder l4 and socket member 20 are thus secured together to form a single mounting unit or member somewhat in the shape of an L, with the base of the holder'resting on the fiat surface 20" formed in the socket 20. The socket member 20 and associated holder l4, as well as the holder l4 at the opposite end of the fixture, are secured to the under surface of the cover plate I 3 by means of bolts 2|, although other securing means may be employed if desired. The upper face 22 of the socket member 20 is provided with a small cliptype socket 23 facing upwardly towards the cover plate l3. The said socket is similar to that shown in United States Patent No. 2,098,080, issued November 2, 1937, to D. K. Wright. The socket 23 is preferably so located in the socket member 20 as to hem substantial alignment with the lamp sockets in the holders l4 so that when the lamp I5 is inserted in place in the said holders, the socket 23 will lie directly underneath the lamp. However,- the socket 23 may be located.

to the outer side of the holder l4 or in any other desired position with respect thereto, instead of the preferred position to the inner side of the holder shown in the drawing.

A small combination thermal switch and condenser unit 24, hereinafter termed a switch unit, is adapted to be mounted in the socket 23. For this purpose, the switch unit 24 is provided with base terminals 25 for engagement with spring contact clips 26 in the socket. Obviously, if desired, the socket 23 and base on the switch unit 24 may be of the screw-threaded or any other suitable type, instead of the clip type shown in the drawing. To permit insertion of the switch unit 24 in the socket 23, the cover plate [3 is provided with a suitable opening 21 directly opposite or above the said socket. Thus the switch unit 24 may be quickly and conveniently inserted in its socket from the exterior of the fixture housing l2.

As shown in Figs. 1 and 3, the switch unit 24, when mounted in place in the'socket 23, projects only a small distance above the cover plate I! so as not to interfere with or prevent the insertion of the lamp l5 between the holders l4. The

switch unit, however, should project a sufiicient distance above the cover plate to enable one to conveniently grasp the same for insertion and removal purposes. .As is evident from Fig. 2, when the lamp I 5 is mounted in place in the fixture, it effectively conceals the switch unit-24 from view, thus preserving the appearance of the fixture.

Mounted within the housing ill, at a point intermediate the holders I4 thereon, is a choke coil or ballast 28 which is secured to the cover plate l3 by any suitable means, such as by bolts 29. The terminals of the choke coil 28, of the socket 23, and the lamp holders l4 are interconnected in the proper manner by suitable connecting leads disposed entirely within the fixture housing It. Thus the only wires extending exteriorly of the fixture housing are the current leads 30 which extend through a suitable bushing 3| in the end wall 32 of the housing to the source of current supply.

Fig. 4 illustrates diagrammatically the manner in which the various auxiliaries are interconnected .to complete the circuit for starting and operating fluorescent lamps of the type now in commercial use, when employing a thermal switch 33 of the-glow discharge type similar to that disclosed and claimed in co-pending United States application Serial No. 289,897, W. C. Smitley, filed August 12, 1939. Thus, referring to Fig. 4, the terminal 34 of one of the lamp holders I4 is connected by lead 33 to one end of the choke coil 28 while the other terminal 35 of said holder is connected by lead 31, which corresponds to one of the screws 20', to the terminal portion 38 of one of the contacts of the starter switch socket 23. choke coil 28 is connected by lead 39, a main switch 40, and lead 4| to one side of the line. The terminals 42, 43 of the other lamp holder l4 are connected by leads 44 and 43, respectively, to the other side of the line and to the other contact 46 of the starter switch socket 23.

The thermal starter switch 33 is mounted in a cylindrical metal container 4'! (Fig. 3) together with a small condenser 48 (Fig. 4) of about 0.05 mfd. to thereby form the combination starter switch and condenser unit24 referred to above, the condenser being connected across the contacts of the thermal switch so as to shunt the same. When the switch unit 24 is inserted in the socket 23, the thermal switch 33 connects the lamp electrodes 43, 50 in series across the line so that upon closure of the main switch 40, a preheating current will fiow through the lamp'electrodes 43, 50. After a short time interval of around 2 seconds or thereabouts, the contacts of the starter switch open, thus throwing the full line voltage across the lamp electrodes and causing the arc discharge to start in the lamp.

Instead of mounting the choke coil 28 within the fixture housing H) as shown in the drawing, it may be mounted separately and at some distance therefrom. In this manner, the undesirable sound of any hum produced by the choke coil may be effectively reduced to a minimum within the room where the fixture is installed. By the use of the particular auxiliaries described hereinabove, this mounting of the choke coil at some distance from the fixture may be accomplished with a minimum number of circuit connecting wires leading from the location of the choke coil to the lamp fixture. Thus, referring to Fig. 4, only the two wires 38 and 44 lead from the location of the choke coil 28 to the lamp fix- The other end of the ture, whereas in the arrangements heretofore in general use four circuit connecting leads were required between the location of the choke coil and the lamp fixture. Therefore, a much simpler wiring system is possible with the particular arrangement according to the invention in the case where the choke coil is to be located at a point remote from the lamp fixture.

Although the thermal switch 33 and condenser 48 are preferably assembled together to form the single switch unit 24 described hereinabove, they may be separated if desired. In such case, the condenser and thermal switch are provided with similar bases adapted to fit into separate and alike sockets similar to the socket 23. The two sockets are preferably provided in separate socket members located at opposite ends of the fixture. condenser are to be connected in parallel in the circuit, they can be freely interchanged in the two sockets without affecting in any way the operation of the lamp. Such an interchangeable Inasmuch as the thermal switch and thelaterally-extending portion provided with a fiat face, one of said receptacle contact elements be- I ing provided with a laterally extending terminal .portion extending into the lateral portion of the member, and conducting means extending from the terminal portion of one of the lamp holder contacts to the said terminal portion of the receptacle contact element for making a series electrical connection therewith and for securing said member and lamp holder together with the base of said lamp holder resting on the flat face of the member. s a 1 3. In combination, a lamp holder having a housing, spaced contacts in a side face of the housing adapted to receive the spaced contact prongs .of a fiuorescent'lamp, said spaced contacts eachbeing provided with terminal portions disposed within said housing, a separate member of insulating-material having a receptacle porfeature therefore obviates the necessity of noting into which socket the thermal switch or condenser is to be inserted.

The socket 23 for the switch unit 24, instead of being located in the upper face 22 of the socket block or member 20 so as to face the top wall I3 of the fixture housing, may be located in the bottom wall or in either of the side walls of the said member, as desired. In such case, the side or bottom wall of the housing opposite the said switch socketis provided with an opening 21 opposite the socket to thereby permit the insertion of the switch unit 24 therethrough. Such analternative arrangement may be used in show case lighting units to thereby provide easy access to the switch unit for replacement purposes.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A device for mounting a fluorescent lamp and auxiliary apparatus on a surface comprising, in combination, a holder for the lamp, said holder having a base portion located on one side of the surface and an extending portion located on the other side, said extending portion being provided with receptacle means in a side face thereof for making an electrical connection with the lamp, a separate member of insulating material carried by said base and having contact means for receiving a replaceable circuit member, said a member being located on the said one side of the ing provided with laterally extending terminal portions disposed within said base, a separate tacle portion including contact elements and a member of insulating material having a recep-' tion including contact elements and a laterally.

extending portion provided with a flat face, the

housing of said lamp holder being carried by said fiat face, one of said receptacle contact elements I being provided with a laterally extending terminal portion extending into the lateraiportion of the member, and conducting means extending from the said terminal portion of one of the receptacle contact elements and extending through the insulating member to the terminal portion of one of the lamp holder contacts for. making a series electrical connection therewith.

4. In combination, a lamp holder having a housing of insulating material, spaced contacts in a side face of said housing adapted to receive a the spaced contact pins of a fluorescent lamp,said lamp holder contacts having terminal portions, a separate member of insulating material carried by and extending laterally from said lamp holder, said member having a receptacle means ineluding contact elements for receiving a con-' tainer having contact prongs, one-of said contact elements being providedwith a terminal portion and screw means threaded into the said one terminal portion of the receptacle .contact element and extending through said insulating member into engagement with one of the terminal portions of said lamp holder contacts for making a series electrical connection therewith. 5. In combination, a lamp holder having a housing, spaced contacts in a side face of the housing and'adapted to receive the spaced contact prongs of a fluorescent lamp, said spaced contacts being provided with terminal portions disposedwithin said housing, a separate member of insulating material having receptacle means including contact elements for receiving a container having contact prongs, one of said lastmentioned contact elements being provided with a laterally extending terminal portion, and screw means extending from the terminal portion of said one receptacle contact element through the insulating member to the terminal portion of one of the lamp holder contacts for making a series electrical connection therewith, and a second screw. means passing through said insulating member and engaging the terminal portion of the other of the lamp holder contacts for mak 'ing an electrical connection therewith.

WARD HARRISON.

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