US2472977A - Fluorescent lamp socket - Google Patents

Description

J1me 1949. H. Y. MAGEocH ET AL 2,472,977

FLUORESCENT LAMP SOCKET Filed Oct. 25, 1947 HARRY YALE MAGEOGH ANDREW J.S

Patented June 14, 1949 UNITED STATES PATENT OFFICE FLUORESCENT LAMP sooner Harry Yale Mageoc'h, Havel-town, and Andrew J. Sha'back, Philadelphia, Pa., assignors to Electric Service Manufacturing Company, Philadelphia, Pa., a corporation of Pennsylvania Application October 125, 1947,, Serial No. 782,126

3 Claims. 1

This invention relates generally to electrical lamp sockets and more particularly to an improved construction of lamp socket adapted for use in conjunction with tubular fluorescent lamps of the type having at each'opposite end thereof a single contact terminal.

Such fluorescent lamps are now frequently installed in passenger vehicles, such as busses, street-cars and railway passenger cars, and it is among the principal objects of the present invention to provide a socket designed especially for use in such vehicles which entirely eliminates the possibility of the tubular lamp being accidentally displaced from its supporting sockets when subjected to the normal shocks and vibrations of a moving vehicle, and which facilitates such mounting of the lamp that the overall length of the lamp and its opposite end sockets is substantially less than the length usually specified as standard for such mounting.

Still another object of the present invention to provide an exceedingly simple and economical construction of a socket for tubular fluorescent lamps which is adapted to be readily installed within restricted spaces in the vehicle; wh-ichprovides a strong and durable support for each end of the tubular lamp; which insures a positive and yet resilient electrical connection between the lamp terminal and the electrical conductor -which supplies current thereto; and which, when employed in complementally mated pairs, makes possible the installation of tubular fluorescent lamps which vary in their lengths within a mount-, ing space measuring considerably less than the length of the lamp tube.

Still another and important object is to provide a socket of the character aforesaid having a mounting flange therefor formed at its front or lamp-receiving end in consequence of which it may be secured in position upon the end wall of a lighting fixture in such manner as to prevent the entry of dust into the fixture by way of the socket mounting, the socket in such case being disposed externally of the fixture so that the tubular lamp-is efiective asa light source throughout the full length of the fixture.

Other objects and advantages of the present invention will appear more fully hereinafter, it being understood that the present invention consists substantially in the combination, construction, location and relative arrangement of parts, all as will appear more fullyhereinaftenas shown in the accompanying drawings and as finally pointed out in the appended claims.

In the accompanying drawings, which are illustrative of a preferred construction of lamp embody'ing the principles of the present invention- Figure 1 is an elevational view showing a typical mounting installation of a pair of the sockets oi the present invention with a tubular lamp supported therebetween;

Figure 2 is an elevational view of the lamp per *se;

Figure 3 is an end view of the lamp per se;

Figure 4 is a front elevational view of one of the pair of lamp sockets, in this instance that one having capacity for substantial axial movement of the lamp relatively thereto;

Figure 5 is a side elevational View of the lamp socket of Figure 4 showing the same in mounted position;

Figure 6 is a vertical sectional view thereof as taken on the line 66 of Figure 4;

Figure 7 is an end view of the other of the pair of lamp sockets, to wit, that one having a capacity iforlimited axial movement of the lamp relatively thereto much less than that of the socket shown in Figures 4 to 6;

Figure 8 is a side elevational view of the lamp socket of Figure '7 showing the same in mounted position;

Figure 9 is a vertical sectional view tl'lereoi as taken on the line 9-4! of Figure 7; and

Figure 10 is a-sectional view typical of each of the pair oisockets as taken along the line Hi-ill 'of Figure 6 orofFigure 9.

--ltieferring now to the drawings, it will be observedthat the socket as constructed in accordance with the present invention is designed to receive a terminal end of a tubular lamp l t 1'2 comprising a supporting pair for the lamp iii are of substantially similar construction.

Thus, eachsocket essentially comprises a main body member [3 of cup-shaped i'orm having a closed end wall M and an external mounting flange I15 embracing its open end, the latter end of the body member being undercut to provide an annular seat ll immediately surrounding the open end of the cylindrical recess it formed in terna'lly of the body member 13. The annular wall of the internal recess 18, adjacent the closed endthereof,is stepped, as at i9, to providean annular 'seatror a metallic contact-plate "23 to which is suitably secured, as by soldering or otherwise,

the bared terminal end of a conductor wire 2| leading from a source of current supply (not shown). The annular seat for the plate is preferably axially spaced from the end wall Id of the socket member I 3 so as to provide a space 22 between the plate 28 and the closed end wall of the socket for accommodation of the insulated portion of the conductor wire 2i which is projected into the socket by way of an opening 23 formed in the cylindrical wall of the body mel iber I3.

Fitted within the open end of the cylindrical body member I3 for axial movement therein is a circumferentially flanged disk 24 having an aperture 25 centrally formed therein, this disk 22 being biased for axial movement outwardly of the socket member I3 by means of a conieally shaped coiled compression spring 26 interposed between the inner contact plate 26 and the outer flanged disk 2%,

said spring being disposed coaxially with respect to the body member I3 and the disks 2c and 2d. Suitably mounted within the reduced end of the conical spring 25 is a relatively short sleeve or grommet 21, the bore of which is in coaxial registry with the central aperture of the flanged disk 24. Preferably, the outer end of the si eve or grommet 21 is provided with an annular flange 28 which extends about and engages the outer convolution of the coil compression 5-. i sure a normal disposition of the she with respect to the spring and to p; I, trical contact seat for the end of minal pin.

In order to limit outward shifting of the disk 24 under the biasing influence of the compression spring 26, the body member I3 of socket I I is fitted at its open end with a collar member 29 the central opening 30 of which is of somewhat smaller diameter than that of the cylindrical socket I 8 and its snugly fitting spring-pressed disk 24. In order to provide for maximum permissible movement of the disk 26 axially of the socket, the collar 29 is preferably provided with an internal annular shoulder 3Il which is so spaced forwardly of the front or open end of the body member I8 that the collar member 29 partially constitutes a continuation of the cylindrical recess I8 of the socket. In order to insure proper registry of the members I3 and 29, the latter is provided with an axially extending annular projection 2i adapted to nest in the annular seat ll of the member I3, the member I 3 and 25 being permanently secured together in their assembled relation as shown by a pair of tubular rivets 32-32. Preferably, the juxtaposed flange portions of the members I3 and 29 are provided with diametrically opposed triangularly shaped mounting extensions 3333 and it is within these extensions that the tubular securing rivets 32-32 are respectively located.

From the foregoing, it will be apparent that in the socket II, the disk 24 is normally urged by its biasing spring 25 into position wherein it resiliently engages the internal shoulder 30* of the outer retaining collar 29, the disk 24 having a capacity, however, of being axially shiftable inwardly of said collar 29.

Substantially the same construction is employed for socket I2 except that the collar member 29 thereof is not undercut to form an internal shoulder, the outer limiting abutment for the disk 24 of socket I2 being formed directly by the inner edge of the collar member 25 In the case one of the sockets, e. g., that designated I I, the cylindrical body portion thereof is of such length as to provide for substantial shifting movement of the disk 24 upon the application of an axial force against its outer face. However, in the case of the other socket, e. g. that designated I2, the cylindrical body portion thereof is so reduced in length as to materially limit the permissible axial shifting movement of its disk 24, the biasing spring spring 29 being so much more compressed in the shorter socket I3 than in the longer socket I 2 as to provide a materially greater resistance to axial shifting of the disk 24 in the shorter socket.

Preferably, each of the sockets I I and I2 is provided at its lamp receiving end with an axial extension 34 which is adapted to project through and so accurately locate the socket within an opening 35 prepared therefor in a supporting panel 36. In use, a pair of the sockets II and I2 are respectively mounted, as by the securing bolts 31-31, in laterally spaced supporting panels 36-36 the distance between which is determined by the length of the tubular lamp intended to be supported between the sockets. This spacing between the sockets is generally such that when the tubular lamp is inserted therebetween, as shown in Figure 1, the end ferrule 38 of the lamp (see Figure 2) is embraced by the collar member 29 of the socket, while the terminal prong 39 of the lamp projects through the apertured disk 26 for electrical contact with the spring-pressed grommet 21 of the socket. It will be understood, of course, that whereas plate 20, the spring 26 and the sleeve 21 are all formed of suitable electrically conductive material, the members I3, 24 and 29 of each socket are formed of suitable electrical insulation material.

In mounting the tubular lamp operatively between the sockets II and I2, one end of the lamp is inserted into the lamp receiving end of the longer socket II with its terminal prong 39 projecting through the central aperture 25 of the spring-pressed disk 24. By pressing the lamp axially against said disk 24, the latter is shifted inwardly against the bias of the spring 2'5 to an extent suflicient to permit the opposite end of the lamp to be presented in alinement with its socket I2, whereupon, by relieving the pressure exerted against the first-mentioned disk 24, the lamp is properly centered between its opposed supporting sockets with its opposite terminal prongs 39-33 in proper electrical engagement with the contact grommets 2I-2'I of the sockets. In such operative position of the tubular lamp, current is delivered to the lamp terminal prongs through the contact plates 2II-20, the compression springs 2626 and the grommets 2!--2'I, while the opposite ferruled ends of the lamp are respectively embraced by the external collar members 29-29 of the sockets, in consequence of which the lamp is secure against accidental dislodgement by reason of any shock or vibration to which the lamp and its mounting may be subjected. To remove a lamp from its operatively supported position between the sockets, it is merely necessary to press one end of the lamp axially against the springpressed disk 24 of the longer socket II, whereupon the opposite end of the lamp is free to be swung laterally of the socket I2, as shown by the dotted line position of the lamp in Figure l, following which it may be readily slipped out of the socket I I. As shown by the dotted lines in Figure l, the sockets II and I2 may each be mounted upon its supporting panel in such manner as to expose the flanged head of the socket frontally of the panel, in which case the closed end of the socket is projected through the panel opening to present the socket in proper position for securement to the panel.

It will be observed that each of the sockets II and I2 is characterized in that it is provided with a mounting flange at its front end and also in that the assembly of the socket during manufacture thereof is effected by way of its front or open end. The internal elements of both sockets, including the spring 26, the plate 26, the disk 24 and the grommet 21, are identical in construction for both sockets and consequently may be interchangeably employed in both sockets with resulting economy in manufacture thereof. Also, by reason of the fact that the sockets are provided with front end mounting flanges, it becomes possible to so mount them, as shown in Figure 1, upon the opposite end walls of a lighting fixture that they project externally of the fixture so that the tubular lamp extending therebetween is effective as a light source throughout the full length of the fixture.

It will be understood, of course, that this invention is susceptible of various changes and modifications which may be made from time to time, all without departing from the general principles or real spirit thereof, and it is accordingly intended to claim the invention broadly, as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. A socket for a tubular fluorescent lamp of the type having a single axially projectin terminal pin at each end thereof comprising a cylindrical body member closed at one end thereof, a centrally apertured disk fitted in the open end of said body member for axial movement therein, a collar member fixedly secured to the open end of said body member, said collar memher having an opening therein of an area sufficiently less than the internal cross-section area of said cylindrical body member to provide an internal shoulder which is engageable by said disk to limit axial movement thereof outwardly of said body member, a spirally coiled compression spring disposed interiorly of said cylindrical body member with its reduced end convolution engaging said disk and in substantial registry with the central aperture thereof for resiliently urging said disk toward said internal shoulder, said sprin being adapted to conduct current to the terminal pin of a tubular lamp inserted into said socket and said collar member being of an axial length sufiicient to embrace a substantial portion of the inserted end of said tubular lamp when the terminal pin thereof is projected into and through the aperture of said disk and into engagement with the registering end convolution of said spring, and a conductor plate fitted in the base of said cylindrical body member to provide a rear abutment for the enlarged base convolution of said compression spring, said plate being in the form of a circular plate of a diameter adated to snugly fit within the closed end of said cylindrical body member and being adapted for electrical connection to a conductor wire for supplying current to the terminal pin projecting from the end of the lamp embraced by said collar member.

2. In a socket of the character defined in claim 1 wherein said cylindrical body member and said collar member are respectively provided with matching flanges and wherein tubular rivets secure said flanges together in fiatwise engagement, the bores of said rivets providing openings for the passage therethrough of elements for mounting the socket upon a support therefor.

3. In a socket of the character defined in claim 2 wherein said collar member is provided with a fiange projecting axially of the open end of the socket, said flange being adapted for projection into an opening formed in the socket support.

HARRY YALE MAGEOCH. ANDREW J. SHABACK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nmnber Name Date 2,186,703 Kresge Jan. 9, 1940 2,253,223 Blake Aug. 19, 1941 2,319,736 Jarmolowsky May 18, 1943 2,393,180 Merrill Jan. 15, 1946

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