US3005177A - Electric light bulb sockets - Google Patents

Description

Oct. 17, 1961 G. WIECKMANN ELECTRIC LIGHT BULB SOCKETS Filed May 14, 1958 2 Sheets-Sheet 1 INVENTOR. Z3 w4w MCKMA/VA/ Oct. 17, 1961 G. WIECKMANN 3,005,177

ELECTRIC LIGHT BULB SOCKETS Filed May 14, 1958 2 Sheets-Sheet 2 INVENTOR.

BY i w Unite grates Patent 3,005,177 Patented Get. 17, 1961 are 3,005,177 ELECTRIC LIGHT BULB SOCKETS Gerhard Wiecinnann, Whitestone, N.Y., assignor to Giibert Manufacturing Ga, Inc, Long Island City, N.Y., a corporation of New York Filed May 14, 1958, Ser. No. 735,332 6 Claims. (Cl. 339-97) This invention relates to electric light bulb sockets used along a pair of insulated, current-carrying conductor Wires and more particularly to an electric light bulb socket in which the wires can be connected to the light bulb contact members in the socket in an expedient manner with a minimum of effort, without cutting or baring the wires, and in such a manner that the wires are provided with strain relief.

The present invention finds particular utility with respect to an electric light bulb socket which is used with a plurality of other similar sockets along a pair of wires, to form a string of light sockets for light bulbs. Such an arrangement is particularly well known, for example in Christmas tree light strings. Because of the relative simplicity of assembly, in many Christmas tree lighting arrangements the light string is connected in series fashion, where but a single wire need be cut and connected to the socket. However, if one of the bulbs of the light string is burnt out, or is out of its socket, the remaining bulbs of the string will also not light. To overcome this disadvantage parallel light string arrangements are used wherein the socket and light bulb are connected directly across the two conducting wires and if any one bulb of the string is burnt out or missing from the string it will not aifect the other bulbs. It has always been a problem to provide a simple construction and mode of assembly for a light bulb socket, capable of being connected in the parallel arrangement, that is economical to produce, easy to securely connect to the electrical conductor wires, and structurally strong.

In the past, a parallel connection has usually been effected by cutting the insulated wires at the desired point of connection to the light bulb socket, or else baring them at those points, and then soldering them to the electrical contact members in the socket. Such a process is expensive and time-consuming and usually the resulting socket construction is such that any slight pull or strain on the wires will separate them from the electrical contact members in the socket.

The present invention overcomes these difiiculties by providing a novel light bulb socket into which the insulated current carrying conductor wires are inserted and contact is made between the wires and the socket contact members with a minimum of effort and without cutting or baring the Wires. The construction of the socket is such, or the wires are inserted into the socket in such a manner, that the wires are provided with adequate strain relief so they cannot be pulled away from the contact members.

It is therefore an object of this invention to provide an electric light bulb socket which can be connected to a pair of insulated wires in a simple and economical manner.

It is a further object of this invention to provide an electric light bulb socket into which the wires are inserted in such a manner as to provide strain relief for the wires.

Yet another object of this invention is to provide an electric light bulb socket so constructed that the connection of the current-carrying conductor wires with the socket contact members is strengthened by strain-relief members in the lamp socket.

A further object of this invention is to provide an electric light bulb socket which has contact members that can be connected to insulated, current-carrying conductor wires without previously cutting or baring the wires.

Other objects and advantages of the invention will become more apparent by an examination of the following specification and accompanying drawings in which:

FIGURE 1 shows a top plan view of one embodiment of the electric light bulb socket together with its connected conductor pair;

FIGURE 2 shows a front elevation view of the husk of the socket of FIGURE 1;

FIGURE 3 shows a side elevation view of the same socket husk;

FIGURE 4 shows a cross-sectional elevation view of the socket taken along line 44 of FIGURE 3;

FIGURE 5 shows a side elevation sectional view of the socket taken along line 55 of FIGURE 2;

FIGURE 6 shows a top plan sectional view of the socket taken along line 6-6 of FIGURE 4;

FIGURE 7 shows a perspective view of one contact member used in the socket of the preceding figures;

FIGURE 8 shows a top plan sectional view, similar to that of FIGURE 6, of another embodiment of the present invention;

FIGURE 9 shows a front elevation sectional view, similar to that of FIGURE 4, of yet another embodiment of the invention;

FIGURE 10 shows a top plan sectional view of the embodiment shown in FIGURE 9 taken along line 10-10;

FIGURE 11 shows a side elevation sectional view, similar to that of FIGURE 5, of the embodiment of FIGURE 9 taken along line 11-11; and

FIGURE 12 shows a bottom view of the embodiment of FIGURE 9.

In accordance with the objects of this invention, a novel electric light bulb socket is provided which is adapted to receive and make contact with two insulated current-carrying wires. The wires are inserted into the lamp socket without being cut or bared at the contact points and contact is made to them, without soldering or other similar process, by contact members in the socket which serve both to secure the wires in the socket and to engage the light bulb when inserted into the socket. The wires, as they are inserted into the socket, are either looped or interlocked and knotted in sucha manner as to provide strain relief or else the socket itself is constructed with strain relief members.

Referring to FIGURES 1-7, the outer husk or housing of the socket is shown as 1 and has an internal hollowed cavity portion 4 with front walls 10 and side walls 8 which extend down into the husk, and terminate at the bottom wall 6. The husk 1 can be made of any suitable insulating material such as porcelain, Bakelite, or any other suitable synthetic plastic material. Socket husk 1 is formed at its lower end with a neck portion 7 which has an opening or aperture 5 that extends through the neck portion 7 and the bottom wall 6, through which wires 2 and 3 make their entry into the cavity 4 of socket husk 1. Aperture 5 can be of any desired shape such as square, rectangular, polygonal or circular. A pair of insulated, current-carrying conductor wires 2, 3 extend into the cavity 4 of the husk 1 through bottom aperture 5 and supply current to the light bulb (not shown) which will be placed in the socket. For purposes of convenient identification, the wire 2 is shown plain and the wire 3 stippled.

The internal construction of the socket can best be seen by referring to FIGURES 1, 4, 5 and 6. The cavity 4 of the husk 1 has a circular flared upper section 9 which gradually tapers to a portion of the cavity 4 where the front walls 10 of the cavity 4 are parallel. The flared section 9 of the cavity 4 can be any shape necessary to accommodate the light bulb to be used. The parallel front walls 10 of internal cavity 4 of the husk 1 are threaded as shown at 12 to accommodate a conventional The side walls 8 of the cavity 4 have recessed grooves 13 which extend from the top of husk 1 substantially all the way down to the bottom wall 6 of the cavity 4 and receive contact members 14, 14.

FIGURE 7 is a more detailed showing of the contact member 14, which comprises a single metal strip which can be made of any suitable conductive material, such as brass. The contact member 14 has a major section 13 of generally rectangular construction with a tab portion 17 punched out of its center. The tab portion 17 extends generally perpendicularly to the major section 18 to form a contact for the center terminal at the bottom of the bulb base. A similar tab portion 17' of contact member 14 is used to make electrical contact with the shell of the bulb base when it is secured in the socket and thereby complete the circuit for the lamp bulb filament. As shown in FIGURE 4, the tab 17 is bent in arcuate shape, extending down from the top of the contact member 14, to form the side contact for the light bulb. Each contact member 14, 14 also has a bottom extending portion 2%) which is narrower than the major body section 18 of the contact member and is also slightly bent in at an angle toward the center of the husk 1. as shown at 51 in FIG- URE 4. The bottom of the extending portion 20 of the blade member 14 is formed with a fiat piece 21 and two sharp pointed contact prongs Z2, 23. These prongs serve to pierce the insulation of wires 2 and 3 and make contact with the inner current-carrying conductors of the wires,

As was previously pointed out, the purpose of the light bulb socket is to secure a parallel connection to a-pair of wires. If a series connection of a plurality of light bulb sockets to a pair of wires is desired, one of the wires will not be connectedto the socket contact members at all and the other wire will be cut and each end connected to a respective contact member. usually by soldering, at the point where each socket is to be replaced. In effecting a parallel connection, the socket contact members must be connected to both wires at the desired point of use. In the present invention, this is accomplished without cutting or baring the Wires and without soldering them, by taking the two wires 2 and 3 and doubling them over to form loops 52, 53, before they are inserted into the aperture of the husk 1. As shown in FIGURES 1, 4 and 6, the loop 53 of wire 3, formed when the wire 3 was doubled over and inserted into the husk 1, is placed inside a similar loop 52 formed by the doubling over of wire 2.

After the loops 52 and 53 of wires 2 and 3 are inserted into the husk 1, the two metal contact blades 14, 14' are forced into the recessed grooves 13 of the husk 1 side walls 8. The grooves 13 are fashioned in such a manner that the contact blades 14, 14 will fit tightly and securely within them. If desired, barbs may be struck out from the planes of contact members 14, 14 to hold them within grooves 13. The prong portions 22 and 23 of the bent-in lower portions 20 of the contact blades 14, 14' are forced through the outer insulation of wires 2 and 3 and make contact with the inner conductors of the wires. The fiat piece 21 of each contact member 14 presses against a respective wire and holds it firmly within the cavity 4 against bottom wall 6, and also against the extended sections 15 of front walls A rigid pin 25, composed of any suitable material, either metal or insulating, is inserted in the husk neck 7 across the aperture 5 below the point where the loops 52, 53 formed by wires 2 and 3 intersect. The loops 52, 53 bend around this pin 25 and since the pin is firmly imbedded in the neck 7 of the husk 1, wires 2 and 3 cannot be pulled out of the husk. In this manner, wires 2 and 3 are provided with strain relief and cannot be easily separated from contact members 14 and 14.

If a lamp bulb is screwed into the socket, the bottom center contact on the bulb base would make electrical contact with the bent tab portion 17 of the left-hand contact member 14 of FIGURE 4, and the side contact portion of the bulb base would make electrical contact with the curved portion 17 of the right-hand contact 14 to complete the circuit for the lamp bulb filament.

Thus FIGURES 1 through 7 show one embodiment of the invention wherein a parallel connection can be made to a pair of current-carrying conductors with a minimum of effort. In actual use, wires 2 and 3 may be looped and inserted into the husk 1 in one machine operation and the two contact members 14, 14' inserted in another. By these two simple operations a complete connection is made. There is no necessity for either baring or cutting the Wires 2 and 3 at the point of contact or for providing any soldered connections, since the prong points 22 and 23 of the contact members 14, 14 pierce through the insulation of wires 2 and 3 to make electrical contact with the inner conductors of these wires. Sharpened points 22 and 23 also secure wires 2 and 3 inside the husk 1 against bottom wall 6 in cooperation with the bent in fiat section 21 of the contact members 14, 14'. The insertion of the pin 25 in the neck 7 of the husk 1,.where the wires 2 and 3 enter the husk 1 at the aperture 5, provides the lamp socket with strain relief means which will insure that wires 2 and 3 cannot be pulled away from the prong points 22 and 23 of blade members 14, 14'. Therefore, novel, efiicient and economical means are provided to fasten the pair of conducting wires in parallel to the contact members of the socket.

FIGURE 8 shows another embodiment of the invention in which wires 2 and 3 are inserted into the husk 1 in such a manner as to provide strain relief without the use of a strain relief pin such as 25, although pin 25 may be used if desired. In this embodiment, those elements which perform the same functions previously described are designated with the same reference characters. A comparison of FIGURE 8 with FIGURE 6 shows that the wires 2 and 3 are interlocked and knotted within the husk 1 in a different manner. In this embodiment, each wire is looped over the other wire inside of the husk 1 to form a knot at 28. It is seen that each of wires 2 and 3 enters and leaves the husk 1 adjacent a respective front wall 10 in distinction to FIGURE 6 in which the wires 2 and 3 are merely doubled over and enter and leave the husk 1 adjacent a respective side wall 8. The knotting is effected by crossing the wires before forming the loops 52, 53.

At the point 28 of the knot of the wires 2 and 3, each wire provides strain relief for the other. For example, if either end of wire 2 is pulled, it will force itself against wire 3 at the knot point 28 and this will prevent the wire from being pulled away from contact prongs 22 and 23. Because of the strain relief provided by the interlocking of the wires, the necessity for a strain relief pin such as 25 is eliminated. The remaining operation and function of the embodiment of FIGURE 8 is the same, namely:

, contact members 14, 14 are forced into grooves 13 and the sharpened prongs 22 and 23 make contact with each of the inner conductors of wires 2 and 3 and the lower portions 20 of the members 14, 14 secure the wires against bottom walls 6. When current is supplied to wires 2 and 3 it will be fed through tabs 17 and 17 of the contact members 14, 14' to a bulb inserted in the socket.

Another form of the socket is shown in FIGURES 9 to 12. Again, in this embodiment, those elements which function in the same manner have been designated with the same reference'characters as those used in the other two embodiments. In FIGURES 9-12, wires 2 and 3 are doubled over to form loops 52, 53 before they are inserted into the husk 1. A separator bar 32, which may be integral with husk 1 or secured thereto, extends completely across the aperture in the neck portion 7 of the lower end of thehusk 1, as shown in FIGURE 12. The separator bar 32, as shown in FIGURE 9, has an outwardly flared upper portion which provides a channel to guide loops 52 and 53 to the opposite sides of the husk 1. The separator bar 32 can be made of any suitable material but an insulating material is preferred.

In the cavity 4, wires 2 and 3 each loop around a respective abutting pin 30 and 30', which extends from the bottom wall 6 upwardly into cavity 4 to a height greater than the diameter of the wire used, to prevent the wires from sliding ofi the pins 30 and 3t). Pins 30 and 30 are also located on bottom Wall 6 so as to give clearance for each wire between a side wall 8 of the cavity 4 and a respective pin 30 or 30. The tapered upper portion of separator bar 32 extends upward into cavity 4 to a point opposite the top of the pins 30, 30' and forms a channel for each of the wires 2 and 3 to guide them toward and over the pins 30, 30'.

When contact members 14, 14', are inserted into grooves 13 the flat pieces 21 and prongs 22 and 23 press against wires 2 and 3 and force them into this clearance portion between the pins 30, 30', and the side walls 8, and against the bottom wall 6, while also making contact with the inner conductors of the wires. Thus, each wire is provided with a strain relief means 30 or 30', which will prevent it from being pulled out of the husk 1 since the wires 2 and 3 are looped over the pins 30, 30'. Separator bar 32 also provides additional strain relief since it limits the amount that wires 2 or 3 can be pulled in a given direction. It is also possible to make separator bar 32 large enough to keep wires 2 and 3 pressed against the sides of the aperture 5, and thereby prevent any movement of the wires 2 and 3.

FIGURE 10 shows wires 2 and 3 looped around pins 30, 30' and also the sharpened prongs 22 and 23 making contact and piercing the insulation of wires 2 and 3. FIGURE 11 shows the wire 2 looped around pin 30 and the pronged portions 22 and 23 of contact member 14 piercing through the insulation of wire 2, while the flat portion 21 forces the wire 2 into the clearance space between the pin 30 and the side wall 8. FIGURE 12 shows the position in which wires 2 and 3 enter and leave the aperture 5 in the embodiment of the invention shown in FIG. 9. It should be noted that each of wires 2 and 3, both enters and leaves adjacent the same side wall 8, since they are only doubled over in the sockets and not twisted in any way. A bottom view of the invention of the embodiments shown in FIGURES 1-6 is similar to FIGURE 12 except that the separating bar 32 is replaced by a pin 25, and the loops 52 and 53 extend toward the side wall 8 opposite from the point of entry. A bottom view of the embodiment of the invention shown in FIG- URE 8, if compared to FIGURE 12, would not have a separating bar such as 32 or a pin such as 25, and would also have the entry and exit positions of wires 2 and 3 changed, i.e. wire 2 would enter the top left section of the aperture 5 of the husk 1 and leave through the top right section, wire 3 would enter through the bottom left section and leave through the bottom right section.

It should be noted that the invention is not, in any manner, limited to a specific diameter wire, or to a specific size husk, but the husk can always be designed to accommodate any diameter wire and any size bulb.

It is therefore seen that a novel electric light bulb socket is provided that can be connected to a pair of current-carrying conductor wires at any point along the wires without cutting or baring the wires or making any connections such as by soldering. Also, the wires are provided with strain relief either by structural strain relief members as a part of the socket or else by inserting 6 the wires into the socket interlocked and knotted in such a manner as to provide the strain relief.

It is obvious that many changes could be made in the above construction and many widely differing embodiments of this invention could be made without departing from the scope thereof. It is intended that all matter and description contained in the above description or accompanying drawings shall be interpreted in an illustrative and not a limiting sense.

What is claimed is:

1. An electric light bulb socket comprising a body portion, said body portion having an internal cavity with two side walls and a bottom wall, said body portion also being formed with an aperture that extends through the bottom wall of said cavity and adapted to accommodate a plurality of continuous, doubled-over, insulated, cur rent-carrying wires when inserted into the cavity, a plurality of pins extending upwardly into said cavity from said bottom wall, each pin adapted to accommodate a respective Wire looped over it to provide strain relief for the respective wire, a plurality of contact blade members each having a sharpened bottom portion, a plurality of grooves in said side walls each adapted to accommodate a respective contact member, the bottom portion of each of said contact members adapted to pierce the insulation of the respective wire and also adapted to press its corresponding Wire against said bottom wall be tween a respective pin and a side wall.

2. An electric light bulb socket comprising a body portion, said body portion having an internal cavity with two side walls and a bottom wall, said body also being formed with an aperture that extends through said bottom wall of said cavity and adapted to accommodate a plurality of continuous, doubled-over, insulated, currentcarrying wires when inserted into the cavity, a plurality of pins extending upwardly into said cavity from said bottom wall, each pin adapted to accommodate a respective wire when looped over it to provide strain relief for the respective wire, a separator member extending across said aperture adapted to provide a channel for a respective doubled-over wire, a plurality of contact members each formed with a sharpened portion, a plurality of grooves in said side walls each adapted to accommodate a respective member, the sharpened portion of each of said contact members being adapted to pierce the insulation of a respective wire to make contact with the inner conductor thereof and also adapted to press its corresponding wire against said bottom wall between a respective pin and a side wall.

3. An electric light bulb socket comprising a body portion, said body portion having an internal cavity with two front walls, two side walls and a bottom wall, said front walls adapted to accommodate the base of a light bulb, said body also being formed at one end thereof with a neck portion having an aperture that extends through the neck and the bottom Wall of said cavity and adapted to accommodate a plurality of continuous, doubled-over, insulated, current-carrying wires, a plurality of pins extending from said bottom wall upwardly into said cavity and spaced from the front and side walls, and adapted to accommodate a respective wire looped around it to provide strain relief for the respective wire, a separator member extending across the aperture from the bottom of the neck into the cavity of the body portion to a point substantially opposite the uppermost portion of the abutting pins to provide a channel for each doubled-over Wire, the 'end of said separator member extending into said cavity being wider than the portion in the neck thereby being adapted to provide a channel for each of said wires, a plurality of contact members each formed with a sharpened portion, a plurality of grooves in said side walls each adapted to accommodate a respective contact member, the sharpened portion of each of said contact members adapted to pierce the insulation of a respective wire and to make contact with the inner conductor thereof and also adapted to press the wire into the space between a respective pin and side wall and against said bottom wall.

4. An electric light bulb socket and parallel-connected cord assembly comprising a body portion, said body portion having an internal cavity with two side walls and a bottom wall, said body also being formed with an aperture that extends through said bottom wall of said cavity, a plurality of continuous, doubled-over, insulated, current-carrying wires each doubled over to form a loop within said cavity, a pin extending upwardly into said cavity from said bottom wall opposite a respective side wall, said doubled wires extending through said aperture and each wire looped over a pin to provide strain relief for the wire, two contact members each having a sharpened portion, each of said side walls having a groove accommodating a respective contact member, the sharpened portion of each of said contact members extending through the insulation of a respective wire and pressing its corresponding wire against said bottom wall between the pin and the side wall.

5. An electric light bulb socket comprising a body portion having an internal cavity including a bottom wall, said body portion also having an aperture adapted to provide entry into'the cavity for a plurality of wires, a plurality of pins extending upwardly into said cavity from said bottom wall, each of said pins adapted to;

have a wire looped around it and to provide strain relief therefor, a plurality of contact members, each of said contact members being adapted to make-electricalcontact with a respective wire and to press it against said bottom wall, and a separator member in said aperture for providing a channel for the ends of a respective looped over wire and for providing additional strain relief for the Wires.

6. An electric light bulb socket as set forth in claim 5, wherein said separator member extends into the cavity of said body portion. 7

References Cited in the file of this patent UNITED STATES PATENTS

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