US1674324A - Electric-light socket - Google Patents

Description

June 19, 192s.-

J. FIGUEIRA ELECTRIC LIGHT SOCKET Filed July 18, 192*! Patented June 19, 1928.

UNITED mm JOSEPH FIGUEIRA, OF 'NEW YORK, N. Y

nLEo'rnIo-LmnT sooner.-

Application filed July 18, 1927, Serial No. 206,400.

This invention relates to electric light sockets and particularly to that type thereof known as pull-chain sockets. As heretofore constructed, these sockets, particularly 6 when used for ceilinglights, have had the switch mechanism thereof enclosed within a porcelain sleeve or casing.

It is the usual and common practice to provide'the ceiling light fixture with a hori- 10 zontally extending flange surrounding the opening through which the screw socket projects, and to secure the socket in position Within the fixture by' means of a small threaded porcelain nut which engages upon the outside of the threads of the socketand serves to clamp one end of the porcelain sleeve above referred to against the flange of the'light fixture.

Electric sockets of the type to which this invention relates are made by many different manufacturers and the differences in the constructional details of such sockets have been such that, with sockets of any particular construction, it has been necessary to use 2 porcelain sleeves made especially to fit such sockets, or in other words, the porcelain sleevesmade for one line of sockets will not fit and can not be used with sockets made by a different manufacturer. In addition, the porcelain sleeves heretofore universally used, being frangible, are not only frequently broken, but in the operation of clamping the socket to the lighting fixture, the sleeves are frequently split or cracked thereby forming a break in the insulation, and as the cracked part of the socket is hidden by the light fixture, if a short-circuit through such break occurs, it is very difficult to locate the trouble.

The principal object of the present invention is to provide a new and improved construction for an electric light socket of the type above de'scribed,'in which'the 'obj'ec tionable features above noted are not only overcome, but which, in addition, will be cheaper to produce than the constructions heretofore employed. Considered. more specifically, another object of theinvention is to provide a new and improved construction for the socket sleeve or casing which will enable the casing to be used universally with pull-chainsockets of different manufacturers. Y

The above and other objects will appear more fully from the following more'detailed description and by reference to the accompanying drawings'forming'a part hereof, wherein Fig. 1 is a central vertical section I through a lighting fixture and socket constructed in accordance with the principles of my invention; Fig. 2 is a section on the line 22 of Fig. 1; Fig. 3is a view of the parts showing them disassembled, but in position to be assembled, and Fig. 4 is a detail in central longitudinal section through the socket sleeve or casing.

As shown in the drawings, the numeral 10 indicates a ceiling light fixture which. may be of any suitable size, shape ordesign and is adapted to be secured to a ceiling by means of the bolts 11. The fixture 10 is adapted to enclose, and form a support for, a pullchain switch socket 12, which comprises a switch section T12 and a socket section 12*, the socket section being pressed orotherwise formed with screw threads for receiving the threaded end of an electric incandescent lamp 13, and the switch sectionhavi-ng the usual switch mechanism therein adaptedto be actuated by the pull chain 14 which passes through the flaring bell-mouthed chain guide 15, anchored to'the switch section,all in accordance with the usual construction of such devices. Y

The switch section 12 is enclosed within a metal casing or sleeve 16, the length of which is approximately equal to that of said section, and said casing is provided with an elongated slot 17, through which is adapted to pass'the bellmouthed chainguide 15. Interposed between the switchsection 12 and the inner wall of the casing 16 is a sleeve 18 constructed of insulating material. In order to prevent relative movement between'the casing 16 and insulating sleeve 18, the latter is provided, adjacent tov the'top and bottom thereof, with inwardly projecting pointed tabs 19 adapted to be imbedded into the material of the insulating sleeve or r to be located within V-shaped notches 100 formed in the top and-bottom edges of said insulating sleeve. The tabs 19 are preferably so located that, when the casing 16 and socket 12 are assembled,the tabs 19 will be opposite to the porcelain parts of the switch section 12f andat a suflicientdistance from the metallic parts of the switch that there will be no possibility of arcing or short circuiting between the tabs and such metallic parts.

For the purpose of holding the socket 12 securely in position within the light fixture 10, the latter is provided with the usual hori zontally extending flange 20, against which is adapted to be seated a flange 21 formed at the bottom of the casing 16. The flanges 20, 21 are formed, one with a notch 22 and the other with a projecting lug or rib 23,

which CO-OPQTflt'GS with said notchto prevent relative rotation between the socket and fixture during the assembling of the parts and also after they. have been .assem bled. The flange 20, as shown in Fig; 1 of the drawing, is formed by crimping or bending the lower edge of the sheet metal of the upper portion of thefixture 10 around the upper flanged edgeof the lower portion of said fixture. The rib 23 provided in the 1 flange 20. is formed by pressing the layers of metal which form the flange upwardly so that, as shown at the right in Fig. 1, the rib projects above the horizontal plane in which the major portion of flange lies. The casing 16 and socket 12 are clamped within the fixture by means of a porcelain nut 24 which is adapted to screw upon the exterior of the usual screw threads of the socket. The porcelain nut is provided adjacent to its upper end with a horizontal flange 25 between which and the flange 21 of the casing 16 the flange 20 of the light fixture 10 is clamped. In accordance with the usual construction of such porcelain nuts, the nut 24 has ,its

, upper end reduced, as at 26, to pass through the opening in the light fixture flange 20, thereby to insulate said flange irom the me tallic screwv threaded portion 12 of the socket.

The manner in which the parts are assembled will be readily understood by referring to Fig. 3. The casing 16 is placed in position within-the fixture 10 with the flange 22-01 said casing in engagementwith the flange21 or said fixture, after which the 2 socket 12 is inserted into the casing so that ture and clamping the flange 20 of the fixture 10 between the flanges 21 and 25 of the casing 16 and nut 24 respectively.

It will be noted that the casing 16 is flared or widened at its lowerend adjacent to the flange 21 to provide ample clearance for the upper reduced end 26 of the nut 24. As

the casing 16 is constructed of metal, it is possible to permit the chain guide 15 to abut against the inner end of the slot 17 and to employ such abutment to transmit to the casing the inward pull exerted upon the socket by the nut 24, thereby to clamp the flanges 20, 21 and 25 securely together. When the casing is constructed of porcelain, contacting engagementbetween the chain guide and the slot provided for it in the casing must beavoided in order that there be no force exerted on the porcelain casing along what may be termed a point or line contact, otherwise the porcelain casing will be split or cracked longitudinally and short cireuiting or arcing between the fixture and socket is likely to occur, consequently when porcelain casings are employed, it is necessaryi'to dimension the casings accurately in accordance with the dimensions of each particular makeof socket with which they are to'be used,

and to provide the socket and'casing with cooperating annular shoulders which will be brought into abutting relationship by the action of the nut 24 and which shoulders when in engagement will prevent contact between the chain guide and the end of its slot. lVit-h the present invention, however, the same accuracy of relative dimensioning between socket and casing is not required, because ample inward movement of the easing and socket is provided tor by the length 01 the threaded socket portion 12 As a result, when the casings are constructed as herein disclosed, they may be made to .a

single standard size, which may be useduni 1 versally with sockets of any make. metal construction of the socket therefore not only obviates the considerable losses due to breakage of the porcelain sockets by the chain guide, but also enables the dealer or installer to carry but a single, standard sized casing, instead of a plurality of such casings. Furthermore, the metal casings are much more durable, as they withstand rough usage that would cause breakage of the porcelain ones. In addition, the manufacturing costs of the metal casings are markedly lower, the

cost thereof, in tact, being about one half that of the porcelain.

I claim:

1. The combination with a pull-chain electric lamp socket having a projecting chain guide, of a ceiling light fixture, a metal casing adapted to encase. the switch portion of said socket, said socket and easing bein adapted to be received within, and secured to said ceiling light fixture, and a nut adapted to engage said socket for securin said socket, casing and fixture in assemble con dition, said casing being provided with a longitudinal slot closed at one end and open at the other, in which said chain guide is adapted to be received, said casing, fixture and nut being provided with co-operating clamping The flanges and said chain guide contacting with preventing relative rotation between said the closed end of said slot and transmitting casin and socket. pressure against said casing produced by 4. combination as set forth in claim 1, screwing up said nut for {clamping said in Which'an insulating sleeve is interposed flanges together. between the socket and casing and said sleeve 2. A combination as set forth in claim 1, and socket are provided with interengaging in which a sleeve of insulating material is parts for preventing relative movement-beinterposed between said socket and easing. tween said casing and said sleeve.

3. A combination as set forth in claim 1, In testimony whereof I have hereunto set 20 i in which the flanges of the casing and socket my hand.

are provided with interengaging parts for JOSEPH FIGUEIRA.

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