US2800635A - Snap-on light socket - Google Patents

Description

0. P. CH'RISTENBERY 2,800,635

SNAP-ON LQIGHT SOCKET Filed March 25, 1956 INVENTOR.

' DOLDHUS P. C\-\\Z\5TENBE2Y ATTQRNEYS July 23,1957

2,869,635 Patented July 23, 1957 2,8i il,635

SNAP-(3N LIGHT SUQKET Doiphus P. Christenbery, Royal Oak, Mich.

Application March 23,1956, SerlalNo. 573,414

3 vClaims. (Cl. 339-99 This invention relates to electric light sockets, and more particularly has reference to a socket for a lamp bulb capable of connection to a standard two-conductor cord at any location along the length of the cord, in a manner to provide an electrical connection between the lamp bulb and the cord.

Summarized briefly, the invention comprises a socket including a lamp-receiving section and a base section, adapted to interfit by snapping of the base section onto the bulb retainer or lamp-receiving section. Confronting, complementary recesses are formed in the contacting faces of the cap or base section, and bulb retainer or lamp-receiving section, defining channels adapted to receive a standard, two-conductor, household electric ex tension cord. Projecting into the recesses of the bulb retainer are prongs adapted to penetrate the insulation of the cord to engage the leads of the cord, the prongs being carried by a disc axially shiftable within the bulb retainer, said disc being spring-biased in a direction to normally retract the prongs from the bulb retainer recesses. The disc includes a first terminal adapted to contact the base contact of the lamp bulb, and a second terminal adapted to contact the cylindrical side Wall of the bulb.

in accordance with the invention, the prongs do not penetrate the cord until a bulb is screwed into the bulb retainer, the inserted bulb biasing the disc against the restraint of the associated springs in a direction to extend the prongs into the mentioned channels.

Among important objects of the invention are the following:

To provide a socket so designed that it can be used whenever a string of temporary lights are wanted, thus particularly adapting the socket for use in Christmas decoration lighting, although obviously many other uses thereof are possible:

To provide a socket which can be snapped onto any standard, household, electric extension cord;

To permit spacing of sockets to dispose them at any desired locations upon the cord;

To permit as many sockets as desired to be used on a single cord, up to the capacity of the cord;

To permit removal of the sockets from the cord for facility in storage;

To allow the cord to be put toany other use after removal of the sockets, since the sockets do not damage the cord;

To eliminate the danger of electric shocks incurred by contact with sockets in which bulbs have not been inserted due to the fact that the socket will not function without a bulb;

To provide a socket which, should one socket be damaged, will not affect adversely the use of the remaining sockets of the string;

To provide a socket that can be used out-of-doors; and

To provide a socket which can be obtained individually, so that one may purchase as many as desired, rather than being compelledto purchase a full string of lights having a predetermined number of sockets.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a perspective view of a fragmentary portion of a standard extension cord, to which a pair of the sockets have been connected;

Figure 2 is an enlarged section on line 22 of Fig ure 1;

Figure 3 is a sectional view on the same cutting plane as Figure 2, with the bulb removed and the prongs contracted;

Figure 4 is a transverse sectional view on line 44 on the same scale as Figure 3; and

Figure 5 is an exploded perspective view of the socket per se.

Referring to the drawings in detail, designated generally at lti is a lamp socket formed according to the present invention. This includes a generally cylindrical bulb retainer body 12 having an axial recess for receiving a bulb, said recess opening upon the outer end of the retainer body. The bulb retainer body, adjacent its inner end, has an externally reduced, cylindrical portion 14, merging into a circular flat bulb retainer base 16 the periphery of which projects beyond or overhangs the portion 14 to provide a circumferential lip upon the base 16 of the bulb retainer body.

At its opposite ends, the bulb retainer body is formed with a flared portion -15 into which the globe portion of i the bulb extends.

Fixedly mounted within the axial recess of the bulb retainer body 12 is a threaded, electrically conductive liner 2s, said liner terminating at its inner end a substantial distance inwardly from the inner end of the recess. Beyond the inner end of the liner 26, within the recess, there is provided a flat, circular disc 22 of electrically insulative material, lying in a plane normal to the axis of the bulb retainer body. The disc has limited movement in a direction axially of the bulb retainer body, between the inner end of the recess and an internal shoulder 24- formed upon the wall of the recess beyond the inner end of liner 20.

Integral or otherwise made rigid with the disc 22, at diametrically opposite locations thereon, are guide lugs 26. These extend parallel to the axis of the bulb retainer body, and have free ends slidably engaged in lug sockets 23 formed in the inner end wall of the recess. Compression coil springs are seated in the lug sockets, and exert a continuous pressure on the lugs tending to bias the disc 22 toward the open end of the recess of the retainer body, into engagement with the lip 24 as shown in Figure 3.

Communicating between the axial recess of the bulb retainer body and side-by-side, parallel channels 34 formed in the outer face of the base 16 (see Figure 5) are small diameter bores 32, and slidable in said bores are conductive prongs 36. One of the prongs 36 is connected to a center contact 38 mounted in the disc and faced toward the open end of the bulb retainer body. The other prong is connected to a resilient elongated, conductive member 40 of zig-zag shape connected to the conductive liner 20.

A circular cap 46 of electrically insulative material is formed with a peripheral flange having an inwardly facing, circumferential groove 48 adapted to receive the lip of the base 16. The material of which the cap is formed is slightly resilient, so that the cap can be snapped onto said lip.

The cap is formed, on its inner surface, with side-byside parallel channels 50, matching the channels 34 so that when'the cap is snapped onto the bulb retainer body,

the channels 34, 50 will cooperate to define side by side passages extending transversely of the socket constituting the present invention. In a commercial embodiment, instead of side by side channels 34 and corresponding channels 50, there might be a single, relatively wide channel 34 in the base 16 and a single, complementary channel 50 in the cap, the channels being of a width such as to permit an electric cord 42, of the conventional flat, two-conductor type regularly used as a household extension cord, to be inserted. 7

In any event, the passages defined by snapping of the cap onto the bulb container body form a conduit within said body open at both its ends and extending transversely of the body, through which the cord 42 extends.

In use of the invention, the prongs will initially retract from the conduit as shown in Figure 3, since the springs 30 are free to expand and shift the disc against the lip or shoulder 24. When, however, a lamp bulb 44 is screwed into the socket with the cord 42 seated in the conduit and the cap snapped onto the bulb retainer body, the base of the lamp bulb will ultimately engage the contact 38 and on further threading of the lamp bulb to its maximum extent, as shown in Figure 2, said bulb will shift the disc 22 inwardly against the restraint of springs 30. 'This will cause the prongs 36 to be projected into the conduit of the cord 42, and the prongs, being sharply tipped at their free ends, will penetrate the insulation of the cord and engage the electrically conductive leads of the cord as shown in Figure 2.

This results in an electrical connection between the cord and the lamp bulb, responsive merely to threading of the bulb into the bulb retainer body, and further, when the bulb is threaded out of the body, the springs will now be free to expand, and will urge the disc 22 back to its normal position shown in Figure 3, to retract the prongs so that there will be no danger of an accidental electric shock should one extend his or her finger into the recess of the bulb retainer body.

It will be readily apparent that any number of sockets can be used upon a single cord, up to the capacity of the cord, and further, standard household electric extension cords can be employed, and can be placed back in regular use merely by removal of the sockets.

Further, the sockets can be spaced along the cord as desired, and in addition, there is achieved the desirable result wherein the electrical connection is made in a protected location within the socket, thus particularly adapting the device for use out-of-doors, where it is exposed fully to the elements. 7

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims. o

What is claimed is: x

1. A snap-on lamp socket for attachment to an electrical .conductor having a pair of insulated, side-by-side leads, comprising: a cylindrically shaped, electrically insulative, bulb retainer body having a threaded recess opening upon one end of the body to receive the complementarily threaded base of a lamp bulb; a conductive element engaged with the side wall of the body within the recess for contacting the side wall of the lamp bulb base, the body having at its other end an end wall fully closing the body at said other end thereof andvhaving a permanent, fixed, connection to the side Wall of the body, said end wall having an outer surface formed with sideby-side channels in which said leads may be placed, the

of the end wall; a cap proportioned to overlie the end wall and having a pair of channels corresponding to those of the end wall to cooperate with the end Wall channels in receiving said leads, said cap including a circumferential flange formed of a resilient, yielding material and having an inwardly opening, undercut groove mating with said first named flange, thus to clamp the leads between the cap and end wall responsive to resilient spreading of the flange of the cap over the flange of the end wall into a position gripping said flange of the end wall; a disc of electrically insulative material shiftable axially of the body and spring-biased in one direction in the recess of the body, said disc being disposed to be shifted in an opposite direction by the inserted lamp bulb, against the restraint of the spring bias of the disc; a pair of prongs carried by said disc and disposed to enter the channels of the end wall on shifting of the disc in said opposite direction, to penetrate the conductor for contacting the leads; and a contact carried by one of the prongs and disposed for engagement by the center contact of the inserted lamp bulb, the other prong having an electrical connection to said conductive element, thus to provide a circuit through the bulb responsive to threading of the bulb into the socket.

2. A snap-on lamp socket for attachment to an electrical conductor having a pair of insulated, side-by-side leads, comprising: a cylindrically shaped, electrically insulative, bulb retainer body having a threaded recess opening upon one end of the body to receive the complementarily threaded base of a lamp bulb; a conductive element engaged with the side wall of the body Within the recess for contacting the side wall of the lamp bulb base, the body having at its other end an end wall fully closing the body at said other end thereof and having a permanent, fixed, connection to the side wall of the body, said end wall having an outer surface formed with sideby-side channels in which said leads may be placed, the end wall being formed with a continuous, circumferential flange projecting outwardly from the body in the plane of the end wall; a cap proportioned to overlie the end wall and having a pair of channels corresponding to those of the end wall to cooperate with the end wall channels in receiving said leads, said cap including a circumferential flange formed of a resilient, yielding material and having an inwardly opening, undercut groove mating with said first named flange, thus to clamp the leads between the cap and end wall responsive to resilient spreading of the flange of the cap over the flange of the end wall into a position gripping said flange of the end wall; a disc of electrically insulative material shiftable axially of the body and spring-biased in one direction in the recess of the body, said disc being disposed to be shifted in an opposite direction by the inserted lamp bulb, against the restraint of the spring bias of the disc; a pair of prongs carried by said disc and disposed to enter the channels of the end wall on shifting of the disc in said opposite direction, to penetrate the conductor for contacting the leads; and a contact carried by one of the prongs and disposed for engagement by the center contact of the inserted lamp bulb, the other prong having an electrical connection to said conductive element, thus to provide a circuit through the bulb responsive to threading of the bulb into the socket, said channels of the end wall and cap being disposed in closely spaced, parallel relation with one at least of the channels being extended substantially diametrically of the end wall, the channels being continuous fully across the end wall and cap with the leads being wholly enclosed by the cap and end wall over the full transverse dimension of the end wall.

3. A snap-on lamp socket for attachment to an electrical conductor having a pair of insulated, side-by-side leads, comprising: a cylindrically shaped, electrically insulative, bulb retainer body having a threaded recess opening upon one end of the body to receive the com- .plementarily threaded base of a lamp bulb; a conduc- 5 tive element engaged with the side wall of the body within the recess for contacting the side wall of the lamp bulb base, the body having at its other end an end wall fully closing the body at said other end thereof and having a permanent, fixed, connection to the side wall of the body, said end wall having an outer surface formed with side-by-side channels in which said leads may be placed, the end wall being formed with a continuous, circumferential flange projecting outwardly from the body in the plane of the end wall; a cap proportioned to overlie the end wall and having a pair of channels corresponding to those of the end wall to cooperate with the end wall channels in receiving said leads, said cap including a circumferential flange formed of a resilient, yielding material and having an inwardly opening, undercut groove mating with said first named flange, thus to clamp the leads between the cap and end wall responsive to resilient spreading of the flange of the cap over the flange of the end wall into a position gripping said flange of the end wall; a disc of electrically insulative material shiftable axially of the body and springbiased in one direction in the recess of the body, said disc being disposed to be shifted in an opposite direction by the inserted lamp bulb, against the restraint of the spring bias of the disc; a pair of prongs carried by said disc and disposed to enter the channels of the end wall on shifting of the disc in said opposite direction, to penetrate the conductor for contacting the leads; and a contact carried by one of the prongs and disposed for engagement by the center contact of the inserted lamp bulb, the other prong having an electrical connection to said conductive element, thus to provide a circuit through the bulb responsive to threading of the bulb into the socket, said channels of the end wall and cap being disposed in closely spaced, parallel relation with one at least of the channels being extended substantially diametrically of the end wall, the channels being continuous fully across the end wall and cap with the leads being wholly enclosed by the cap and end wall over the full transverse dimension of the end wall, the prongs entering the channels of the end wall medially between opposite ends of said channels of the end wall, so as to effect penetration of the insulation of the conductor at locations inwardly a substantial distance from the outer surfaces of the cap and body.

Smith Feb. 14, 1916 Gilbert July 28, 1953

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