US 2721985 A
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Description (OCR text may contain errors)
Oct. 25, 1955 c. E. GILBERT 2,721,985
LAMP SOCKET APPARATUS Filed March 30, 1950 3 Sheets-Sheet 1 INVENTOR.
CHARLES E. GILBERT ATTORNEYS Oct. 25, 1955 c. E. GILBERT 2,721,985
LAMP SOCKET APPARATUS Filed March 30, 1950 3 SheetsSheet 2 5J5. czl. 2..
INVENTOR. CHARLES E. GILBERT D n/4 Z ATTORNEYS Oct. 25, 1955 c. E. GILBERT LAMP SOCKET APPARATUS 3 Sheets-Sheet 3 Filed March 50, 1950 p WE. f 1 3 W/ L M m 2 c m w A..- i J E W m m i v l. 9 5 a a y M y j ./L I m em 1 M 1 3 2 9 ATTORNEYS Unite States Patent OflEice LAMP SOCKET APPARATUS Charles E. Gilbert, New York, N. Margaret Doris Gilbert, Norman Coates, and The Chase National Bank of the City of New York, executors of said Charles E.
Gilbert, deceased Application March 30', 1950, Serial N 152,934 2 Claims. Cl. 339 -180) The present invention relates to lamp sockets and their associated equipment and is particularly concerned with lamp sockets adapted to be fastened to a hickey or similar device such as in candelabra types of lamp sockets and to lamp sockets adapted to be associated with prongs rigidly secured thereto to serve as plug-in lights or nightlights.
Qne of the objects of the invention is to provide lamp sockets of these types which are simple to fabricate and to assemble with a minimum number of parts and assembly steps.
A further object is to provide lamp sockets of these types having contact members which may be quickly and easily secured in place in permanent manner as a step in connecting to conductor cords where desired.
It is still another object of the present invention to provide lamp sockets in which the bulb may be securely held in place so as not to loosen as a consequence of vibration or the like.
Various other objects and advantages of the invention will appear more fully from the following detailed description of illustrative embodiments thereof, taken in conjunction with the appended drawings, in which,
Figure l is an elevational cross-sectional view of a candelabra type lamp socket and its mounting hickey;
Figure 2 is an elevational cross-sectional view of the device of Figure 1 taken along line 22 thereof;
Figure 3 is a top view of the lamp socket shell of the preceding figures;
Figure 4 is a bottom view of said shell;
Figure 5 is a side elevational view of said shell;
Figure 6 is a further side elevational view taken perpendicularly of the view of Figure 5; I
Figure 7 is a perspective view of a hickey adapted for ready assembly with the shell of Figures 1 to 6;
Figure 8 is a developed view of one of the contact members adapted to be assembled with the shell of Figures 1 to 6;
Figure 9 is a similarly developed view of another contact member;
Figures 10 and 11 are respective perspective views of modified forms of the hickey of Figure 7;
Figure 12 is an elevational cross-sectional view of a lamp socket according to the present invention having contact members integrally formed as plug prongs for insertion into a plug receptacle; 7
Figure 13 is another elevational cross-sectional view along line 1313 of Figure 12;
Figure 14 is a top view of the lamp socket shell of Figure 12;
Figure 15 is a bottom view of said shell;
Figure 16 is one side view of said shell;
Figure 17 is another side view of said shell viewed perpendicularly to Figure 16;
Figures 18 and 19 are respective developed views of the two contact and prong members of Figures 12 and 13.
Referring to Figures 1 to,9,' there is shown both in 2. assembly and detail a form of lamp socket adapted for use in candelabra type mountings in which", as is well known, the lamp socket proper is mounted on the end of a conduit by means of a hickey which spaces the socket from the end of conduit, a tubular masking member (such as of cardboard, plastic or the like) being slipped around the lamp socket to conceal it and the hickey and to simulate the appearance of a candle, the
bulb when placed in the socket then appearing as the lighted up of such a simulated candle.
In Figures 1 and 2' such a system is shown comprising a conduit 21 to whose end 25 is affiXed a hickey 22 carrying the lamp socket shell 23 which has mounted therein the contact members 24 and 26', the assembly of shell 23, hickey 22 and the end 25 of the conduit 21 being concealed by the tubular masking shell 28 which may be formed or decorated to simulate a candle stick, so that upon positioning the lamp bulb 27 therein a simulated can'dle effect is provided.
The shell 25 is formed of a single, threaded, preferably molded, insulating piece whose outward appearance is shown more in detail in Figures 3", 4, 5 and 6'. As shown in Figures 1, 2 and the shell 23 has formed (pref erably molded) therein threads 31 formed in two separate discontinuous sections separated by two diametrically opposed recesses 33, 34' having straight parallel side's. These recesses 33, 34 are adapted to retain the contact members 24, 26, as will be described. Projections 35 extending toward one another from opposite sides of the recess 33 form a narrow groove at the outer end of recess 33. Similar projections 36' form a similar groove at the outer end of recess 34.
As shown in Figures 1 and 8', contact member 24 is formed of a single strip of brass or similar conductive material having a wide portion 41 and a narrower per: tion 42 bent at the line's- 43 to produce a doubled-over section 44 (as shown in Figure 1) and a contact-making section' 46 which resiliently cooperates with the center terminal of the bulb base as shown in dot and dash lines in Figure 1 to make electrical contact therewith. The width of the wide portion 41 is slightly smaller than the width of recess 33, but larger than the separation between projections 35, so that contact 24- may be inserted in the groove at the end of recess 33, and retained there by projections 33. The narrow portion 42 of the contact member 24 is narrow enough as to pass freely between the projections 35 of the recess 33, which projections, however, prevent the wider portion 41 of contact member 24 from entering the central cavity of the shell 23.
The contact member 26 is formed of a single uniform width strip of material similar to contact member 24, and has a narrow ear 4'7 struck out from the center thereof. This car 47 passes freely between the projections 36 of the recess 34 of shell 23 while the main portion is retained at the end of recess 34 by these projec tions and prevented from entering the main cavity of shell 23. As will be seen from Figure 1 this ear 47 extends inwardly of the shell to a slight extent beyond the innermost edge of the threads 31 so that upon screw ing the bulb 49 into the socket it will make resilient eon= tact with the ear 47 at the bulbs outer threaded periph= ery to provide the necessary second electrical contact for the bulb.
As seen in Figure 3, the base of the shell 23 has a pair of apertures 51 through which the individual conductors 52 of the connecting line may pass, as indicated in Figure 1. In assembling the contact members 24 and 26 the shell 23, the conductors 52, after having their ends' stripped of insulation, are fed through the apertures 51 to a position just above the upper edge of the shell. The contact members 24, 26 are then forced down into their grooves in a manner to retain the stripped portion of Patented Oct. 25, 1955 the conductors 52 between the contact members and the insulating shell wall. The clearance therebetween is made sufficiently small so that the stripped ends of the conductors 52 are crushed against the contact members 24, 26 to make good electrical contact therewith. The upper corners 45 of the contact members 24, 26 are bent slightly to form projections which dig into the wall of shell 23, as shown in Figure 1, and prevent loosening or removal of the contact members. Radially inward of each of the recesses 33, 34 is a respective projection 54 standing up from the inside of the base of shell 23 and having a V-shaped profile as best seen in Figure 2. Each conductor 52 passes over this V-shaped projection 53 to provide a strain relief so that any pull of the conductor 52 will be opposed by the shell 23 rather than resulting in any strain or separation between the conductor 52 and the contact member 24 or 26.
The base of the shell 23 is provided with a pair of further apertures 55 preferably along the diameter transvers to the line joining the apertures 51. These apertures 55 are rectangular in shape and are adapted to receive the tips 61 of the hickey 22 shown in Figure 7. This hickey 22 is essentially a U-shaped bracket having a pair of legs 62 joined by a center section 63 which may have a threaded boss 64 formed at its center, as by extruding, pressing or threading. Each of the tips 61 is joined by means of a narrow neck 67 to a respective shoulder 66 projecting from each leg 62 of the hickey. Shoulder 66 and tip 61 are of the same width as the length of the slotted apertures 55 in the base of the shell 23, and the height of the shoulder 66 and neck 67 are slightly less than the thickness of the bottom of shell 23. For assembly purposes the tip 61 and neck 67 of each of the legs 62 is inserted in a respective opening 55 so that the shoulder 66 passes through the slot 55 with the tip 61 extending above the floor of the base of the shell 23. Then simply by means of a pair of pliers or like instrument the tip 61 is twisted from 45 to 90 with respect to the plane of its leg 62 thereby retaining the hickey fastened securely to the shell 23. It will be understood that the upper edges 68 of the hickey legs 62 bear against the flattened underside of the shell 23 as seen in Figure 4 and the tapered undersides 69 of tips 61 bear against the edges of the slots 55 to hold the hickey securely fastened to the shell. The hickey and shell assembly may then be readily screwed on the threaded end of the conduit 21. The masking shell 28 may then be readily slipped over the lamp socket shell 23 to be frictionally engaged therewith and to conceal the hickey 22 and the end of the conduit 21.
While one form of hickey has been illustrated in Figure 7 it will be understood that many other forms are possible and may be used where desired. Figures 10 and 11 illustrate two further forms of hickey. In Figure 10 the hickey is formed of a single strip of metal or similar material with one of the tips 61a formed in the end thereof as in Figure 7 and the second tip 61b formed on the end of an ear 71 struck out from a transversely extending section 72 of the hickey. Thus, only a single leg 73 corresponding to leg 62 on Figure 7 need be provided, joined to a further transverse portion 74 correspondinng to end 63 of Figure 7 and having the threaded boss 75 corresponding to boss 64 of Figure 7. Figure 11 shows a further form of hickey whose shell securing end is the same as in Figures 7 and 10, but instead of being adapted to be threaded upon a conduit as in Figures 7 and 10, in this form of the invention the side 73 is provided with a slot 74 which may be secured to any desired surface 81 by means of a clamping screw 82 or the like. The transverse portion 74 of the hickey shown in Figure 10 is here unnecessary and is omitted.
In many conventional forms of lamp socket the bulb 27 is screwed into the socket shell until its lower tip 30 makes contact with the center socket contact corresponding to 46 which is resilient to maintain contact with the bulb tip 30. Under these circumstances the bulb 27 is not rigidly held by the socket and during use any stray vibration or shock or the like tends to unscrew the bulb in the socket until eventually the pressure between the center socket connection and the bulb tip is of such light pressure as to cause arcing or to cause disconnection. According to the present invention, however, the socket shell 23 is provided with a plurality of upstanding projections 80 illustrated in Figures 1, 2 and 3 as four in number and symmetrically located. These extend above the projections 54 and the conductors 52 as well as above the twisted tips 61 of the hickey when assembled. In this way, when the bulk is screwed into the socket a positive tightening is accomplished by advancing the bulb 27 in the threads 31 until the edge of the base of the bulb engages the projections 80. These projections are so located that the elastic limit of the lower contact 46 is not exceeded. In this way the bulb is retained in fixed position continuously and constant pressure between the socket contact 46 and the bulb terminal 30 is maintained at all times.
Figures 12 through 19 show another form of lamp socket according to the present invention. Illustratively, this is shown as a socket for candelabra sized lamp bulbs whereas Figures 1 to 11 have been illustrated with respect to medium base lamp bulbs. However, it will be understood that the features of the present invention do not depend in any way upon the size of the socket or the lamp bulb base with which it cooperates, but may be used with any size base.
The lamp socket of Figures 12 to 19 is designed especially for use as a plug-in lamp such as used for a nightlight or guard-light or the like, and for this purpose the contact members for the lamp socket are extended integrally to form the prongs of a plug adapted to be directly inserted into a plug receptacle such as a wall outlet or the like. In this way this device has but three parts readily assembled in the manner to be described, these parts being shell 91 and the two contact-prong members 92, 93. As in the above figures, shell 91 is molded with a pair of threaded sections 94 separated by diametrically opposed recesses 96, 97 having projections 98, 99 forming narrow grooves 101, 102 for receiving the contact members. In this instance, however, the grooves 101, 102 extend completely through the base 103 of the shell 91 as shown most clearly in the bottom view of Figure 15.
The contact member 92 is shown in developed view in Figure 18 and comprises a long section 104 and a short section 105 adapted to be folded back about line 106 to form the prong portion of element 92. The smaller portion 105 has a narrow section 107 adapted to be bent at line 108 to form the central socket terminal 109 as shown in Figure 12. Struck out of the narrower section 107 is a small car or lug 111 adapted to be bent about dotted line 112 to form a transverse projection as shown in Figure 12. It will be understood that the section 107 is narrower than the separation between the projections 98 of Figure 14 so that wider sections 104, 105 are retained within the groove 101, and the narrower section 107 in the form of socket contact 109 and the lug 111 may project into the central cavity of the shell 91. In assembly the bent contact member 92 is inserted through the top of the shell 91 and slid downwardly along groove 101 until lug 111 reaches the inside face of the base 103 of shell 91. The corners 112 of the end of the longer section 104 are bent in as shown at 113 so that during the insertion of the member 92 these points 113 dig into the side wall of the shell material and thereby prevent the element 92 from being moved upwardly of the shell. While this is a simple expedient which is found to be simple and convenient in practice, it will be understood that where desired other means of preventing removal of the member 92 may be utilized such as suitable detents, shoulders or the like.
The contact member 93 is illustrated in Figure 19 and comprises a longer portion 116 and a shorter portion 117 adapted to be bent back in juxtaposition to portion 116 about a line 118 to form the prong portion of member 93. The short portion 117 has a small ear 119 extending therefrom adapted to be bent transversely of the prong portion about a line 121 to form a locating ear similar to 111, as seen in Figure 12. Struck outwardly from the center of the longer portion 116 is a strip 122 having a slanting portion 123 and a parallel portion 124 as shown in Figure 12. This provides a lamp bulb base engaging contact similar to 47 of Figure 1. Again, the corners 126 of the longer portion 116 are bent over to form points which engage the side wall of the shell 91 so that after placement of the member 93 in slot 102 it cannot be withdrawn from the socket shell.
To provide a positive tightening action characteristic of the present invention a pair of ledges 131 are formed on the inner surface of the shell wall extending above the inner surface of the shell base 103 and serving the same purpose as the projections 80 of Figure 3.
Accordingly, several forms of lamp socket have been described, according to the present invention, incorporating a positive tightening active for the lamp bulb preventing loosening thereof during use and maintaining positive contact with the contact members of the socket. As additional features of the present invention there has been shown an extremely simple and inexpensive method of forming both the lamp socket shell and its hickey to provide simple and positive securing of one upon the other. As an additional feature, an extremely simple and inexpensive combined lamp socket and plug arrangement has been shown having but three parts which may be readily made and easily assembled.
While several embodiments of the present invention have been described and illustrated in detail, it is to be understood that these embodiments are exemplary only and are not to be considered in any way as limiting the present invention, since many minor variations therefrom can be readily conceived without departing from the spirit of the present invention, which is defined solely by the appended claims.
What is claimed is:
1. An electrical socket receptacle for electric light bulbs comprising a hollow insulated body open at one end to receive an electric light bulb and having side walls and a base, with a pair of grooved recesses formed on the interior of said side Walls, electrical contact members slidably seated in said grooved recesses and adapted to make electrical contact with the base of said bulb, said contact members being provided with means at their lower ends to make electrical contact with the Wires of an electrical conductor cord, one of said contact members having a resilient tongue bent over therefrom, said tongue extending across the interior of said base and being spaced therefrom the interior walls of said hollow body having threads formed therein and extending between said grooved recesses and adapted to receive said bulb, said body wall also having projections extending upwardly from said body base to make contact with the bulb radially outwardly of its central contact and to restrict movement of said bulb base after contact with said tongue and provide positive clamping means for said bulb base, whereby accidental loosening of said bulb in said hollow body is inhibited.
2. An electrical socket receptacle for electric light bulbs comprising a hollow body of insulating material having a pair of oppositely disposed grooved recesses formed on the interior thereof, said body also having an end wall and being open at the opposite end thereto, a pair of electrical contact elements slidably seated in said grooved recesses and provided with means at their lower ends adjacent said end wall to make electrical connection with the respective wires of an electrical conductor cord, one of said contact members having a resilient portion spaced from the interior face of said end wall and extending parallel thereto and at right angles to the side wall inwardly of said hollow member to substantially the center thereof to make electrical contact with the center base terminal of an electric light bulb and the other electrical contact member being provided with a projection extending but slightly inwardly of said hollow body member and generally axially thereof and adapted to make electrical contact with the threaded shell of the base of an electric light bulb, the end Wall of said hollow body having a plurality of projections formed integrally thereon extending inwardly and parallel to the axis of said hollow body and adapted to engage the bottom of said bulb base after said base engages said resilient contact member portion and before engaging said end wall, said hollow body being internally threaded to receive the threaded bulb base whereby said wall projections and said threaded portion serve to rigidly retain said bulb within said hollow body and in electrical contact with said contact members.
References Cited in the file of this patent UNITED STATES PATENTS 726,832 Ritchel Apr. 28, 1903 1,727,148 White (B) Sept. 3, 1929 1,743,929 Nero Jan. 14, 1930 1,820,261 White Aug. 25, 1931 2,229,403 Benander Jan. 21, 1941 2,309,311 Grohsgal Jan. 26, 1943 2,422,393 Bryant June 17, 1947 FOREIGN PATENTS 731,864 Germany Feb. 17, 1943