Electric socket adapter

A socket adaptor is provided for use with light bulbs in either 110 V or 220 V circuits. The device includes a housing having first and second ends for placement into a light bulb socket and retaining of a light bulb respectively. The interior of the housing may include a circuit board with a rectifier fastened thereto. The circuit board may also have a thermistor and a bridge rectifier fastened thereto.

BACKGROUND OF THE INVENTION 
This invention relates to an energy saving device and more particularly to 
one which reduces power consumption by electric light bulbs or lamps, 
thereby prolonging their life. The use of direct current as well as 
reduced RMS voltage to extend the life of an incandescent light bulb is 
well known. In many such devices, a half-wave rectifier is secured to the 
base of a light bulb prior to the bulb's insertion into a conventional 
socket. By reducing the effective voltage applied to the bulb filament by 
imposing a lower effective voltage thereupon, the operating life of the 
bulb is substantially extended, in some cases enabling a bulb to operate 
for a period of time many times greater than its ordinary expected life. 
An example of this type of device is shown in Niskin, U.S. Pat. No. 
4,350,931. 
Regardless of the type of bulb for which electric bulb savers have been 
designed, a number of shortcomings have presented themselves. First, the 
brightness of the lamp is drastically diminished. Second, many of the 
devices have become dislodged from the bulb base and upon removal of the 
bulb from the socket for insertion of a replacement bulb therein, the 
device may become stuck in the socket so as to preclude its successful 
orientation with respect to the replacement bulb and the electrical 
connections of the socket. This problem is acerbated when a large or 
weighty lamp is involved and the socket is upwardly facing. An additional 
problem arises when dealing with 220 V bulbs, since they are designed to 
be pressed into their socket and then rotated approximately 150. The 
combination of pressure and subsequent twisting tends to permit relative 
movement between the rectifier unit and its electrical contact, which may 
result in the bulb not working properly. 
Therefore it is apparent that the need exists for a simple, yet dependable 
electric bulb saver which may include any combination of a rectifier, 
thermistor and SCR bilateral switch that ensures that the aforesaid 
components make solid contact with the bulb. 
SUMMARY OF THE INVENTION 
In accordance with this invention, a socket adapter having any combination 
of a rectifier, bilateral SCR or thermistor housing therein is provided 
for advantageous use with incandescent light bulbs. The socket adapter 
includes a housing having a first end which is capable of being placed 
into a bulb socket designed for use with a light bulb, and a second end 
capable of retaining a light bulb therein. The housing serves to connect 
as well as separate the first end portion from the second end portion. 
Means are provided for retaining the first end portion in an electrical 
socket, as well as means for retaining an electric light bulb in the 
improved socket adapter. 
Bulb contacts extend from the first end portion of the housing into the 
second end portion of the housing in the preferred embodiment. In that 
first end portion of the housing, a rectifier is securely positioned 
between the socket contacts and the bulb contacts. The rectifier may be 
securely attached as well to a circuit board. Modified embodiments include 
the positioning of a thermistor, as well as a bridge rectifier, in the 
electrical circuit of the socket adapter. 
Additionally, the housing can be fabricated for use with light bulbs of the 
bayonet type. In this embodiment of the invention, the electrical contacts 
are attached to a circuit board having at least a rectifier positioned 
thereon, with circuit connecting means secured to the electrical contacts 
adjacent the electrical outlet, as well as to the bulb engaging rods which 
extend into the second end of the housing for contacting an electric light 
bulb. Additional components, including a thermistor and a bridge 
rectifier, may be used in modifications of the basic invention. The 
primary objective of this invention is to provide an electric socket 
adapter that significantly prolongs the life of light bulbs used with 
either 200 V or 110 V circuits. 
Another objective is the providing of an improved socket adapter for use as 
an electric bulb saver which can be easily secured in a socket as well as 
secured to an electric light bulb. 
These and other objects and advantages of this invention will be apparent 
from the following description, the accompanying drawings and the appended 
claims.

DETAILED DESCRIPTION OF THE INVENTION 
Having reference to the drawings, attention is directed first to FIG. 1 
which illustrates a socket adapter embodying this invention and designated 
generally by the numeral 20. This socket adapter has a housing 21 similar 
to the conventional housings found in socket adapters for use in 110 V 
circuits. As can be seen, the housing includes a first end 22 and second 
end 23. The first end 22 is capable of placement into a bulb socket 
designed for use with a light bulb by means of outer threaded portion 25. 
Outer threaded portion 25 makes electrical contact with the circuit by 
means of a metal sheath 26 secured to the outer surface thereof. Another 
socket contact is facilitated by metal tip 27. 
The second end portion 23 includes an annular side wall 28 having an inner 
threaded portion 29 such that the second end portion is capable of 
retaining a light bulb therein. A pair of metal strips serve as bulb 
contacts, with one of the bulb contacts extending adjacent the side wall 
28 while the second bulb contact extends relatively perpendicularly 
thereto. 
In the embodiment of the invention shown in FIGS. 1-3, the bulb contacts 
extend from the second end of the housing into the first end portion of 
the housing. As in conventional 110 V sockets, one of the bulb contacts 
passes through an aperture in the outer threaded portion 25 and is secured 
between it and metal sheath 26. However, whereas the other bulb contact 
extends through socket bottom 31 by means of bottom apertures 32 so as to 
terminate in metal tip 27, this invention includes the positioning of a 
rectifier in the first end portion of the housing. 
As can be seen in FIGS. 2-6, a rectifier 33 is positioned between bulb 
contact 30 and tip extension 34 with electrical contact being made with 
those elements by circuit connecting means 38 which may be wire or 
electrical fastening means such as solder. The presence of the rectifier 
reduces the effective voltage applied to the bulb filament. The rectifier 
used in this invention preferably is a sidac with a V.sub.bo of 100 V. The 
rectifier is shown on a circuit board 36. The circuit board is 
approximately 1/8" thick and is fabricated from a suitable material such 
as plastic or wood. Depending upon the structural integrity of the 
components of the socket adapter, it may be possible in socket adapters 
for use with 110 V circuits to omit the circuit board if the rectifier is 
securely maintained in electrical contact with the bulb contact and tip 
extension. If a circuit board is used, it may be advantageous to secure it 
to a portion of the inner wall of outer threaded portion 25. 
FIG. 5 shows a thermistor 40 being connected in series with rectifier 33, 
with this thermistor being of the negative temperature coefficient type. 
The thermistor has an R value at 250.degree. C. of between 10 and 100 
ohms, while its R at 75.degree. C. is considerably less. The thermistor 
has a preferred power dissipation of under two watts, a soft glow time 
from zero to maximum brightness of 1-3 seconds. The presence of a 
thermistor will help to extend a bulb's life and is particularly desirable 
if the light bulb with which the socket adapter is used is turned 
on-and-off somewhat frequently. The use of an embodiment with a thermistor 
will not impact on brightness, but only on the stress the bulb encounters 
when the initial rush of current occurs. If the filament is weak, the 
normal switching on of the bulb may cause the filament to break. 
Yet another embodiment is shown in FIG. 6, wherein in addition to a 
thermistor, a bridge rectifier 42 is included in the circuit of this 
invention. Preferably the bridge rectifier has a PIV of 300 V or more, an 
I.sub.f of 1.5 amperes or more and a V.sub.f of approximately one volt. 
FIG. 7 discloses an improved socket adapter in the preferred embodiment for 
use of this invention for use with light bulbs of the bayonet type. The 
socket adapter for use with light bulbs of the bayonet type has a housing 
61 with first end 62 and second end 63. First end 62 is capable of 
placement into a bulb socket for use with a light bulb of the bayonet 
type, since it features bayonets 64 as well as electrical contacts 65. 
Extending from these electrical contacts into the interior of the housing 
61 are rods 67, the ends opposite electrical contacts 65 being secured to 
circuit board 68. A rectifier 69 is positioned adjacent circuit board 68 
and is secured to one of the rods 67 by circuit connecting means 70. 
Additionally, the sidac used in this type of embodiment should have a 
V.sub.bo of around 200 V. 
Spring biased bulb engaging rods 71 extend away from circuit board 68 and 
project into the second end portion 63 of the housing. On their way, the 
bulb engaging rods 71 also pass through a planar portion 72 of housing 61 
which serves to separate the first end portion from the second end 
portion. Circuit connecting means 70 extend from one side of the circuit 
board to the other, where contact is made with the bulb engaging rod 71. 
To facilitate this contact, the diameter of the circuit board 68 is less 
than the inner diameter of housing 61 at the location where the circuit 
board is maintained. A pair of L-shaped slots 33 serve to retain the 
bayonets of a light bulb in the second end portion 63 while the bulb 
engaging rods 71 make electrical contact with the light bulb itself. 
FIGS. 9 and 10 show modifications of the embodiment for use with light 
bulbs of the bayonet type. FIG. 9 discloses a thermistor 74 which may be 
identical to thermistor 40, with thermistor 74 being in series with 
rectifier 69. FIG. 10 discloses a modified embodiment which also includes 
a bridge rectifier 75. In the embodiment for use with light bulbs of the 
bayonet type, although the thermistor may be the same as the one used in 
110 V circuits, the bridge rectifier would have a PIV of 400 V or more, an 
I.sub.f of at least one amp and a V.sub.f of approximately one volt. 
FIGS. 11 and 12 show yet another modified embodiment of the invention. The 
embodiment shown in FIG. 11 discloses the utilization of three metal 
plates 81, 82 and 83 which are separated from each other by insulating 
material 84. Positioned between first and second plates 81 and 82, 
respectively is a rectifier or SCR bilateral switch 85 which is in 
electrical connection with the plates. Thermistor 86 is positioned in 
electrical connection between the second and third plates, 82 and 83, 
respectively. 
A bimetal strip 87 having one metal forming its upper surface 88 and 
another metal forming its lower surface 89 is shown as being located on 
third plate 83. On opposing second plate 82 is a contact point 90, which 
strip 87 contacts as strip 87 bends in response to the passage of current 
through it. Once contact is established, the current no longer flows 
through the thermistor 86, thus eliminating the power dissipation 
associated therewith as well as the generated heat which over time can 
adversely effect the socket where the invention is maintained. When the 
current ceases to flow, strip 87, as it cools, returns to its initial 
configuration. This embodiment could be used with conventional 110 V 
circuits. 
FIG. 12 discloses a modified embodiment similar to the one just discussed, 
but for use with light bulbs of the bayonet type. As can be seen, there 
are three plates 91, 92 and 93, each of which has a cut out portion 94 to 
facilitate the AC connector associated with the bulb. On the second plate 
is rectifier or SCR bilateral switch 95, while on the third plate 93 is 
thermistor 96. Bimetal strip 97 is formed and acts just as strip 87 does 
in the embodiment shown in FIG. 11. When assembled, the plates of FIG. 12 
should also have insulation therebetween. The structure of FIG. 12 behaves 
just as the one in FIG. 11. These modified embodiments may be substituted 
for the circuit board embodiments shown in FIG. 5 and 9 if desired. 
Use of a sidac in either the 110 V or 220 V embodiments results in an 
insignificant loss of light, since energy in both parts of a cycle is 
used. 
in actual operation, the improved socket adapter of this invention may be 
positioned in a normal electrical socket, at which time the appropriate 
type of light bulb can be inserted therein and secured. 
It will be readily apparent from the foregoing detailed description of the 
preferred embodiment and the several modifications thereof that a 
particularly novel and extremely effective socket adapter is provided. The 
device is relatively simple to fabricate, since it resembles socket 
adapters currently on the market, however, it results in a device which 
provides a significant increase in extension of bulb life while increasing 
the dependability of this type of unit over bulb savers previously known. 
While the form of apparatus herein described constitutes a preferred 
embodiment of this invention, it is to be understood that the invention is 
not limited to this precise form of apparatus, and that changes may be 
made therein without departing from the scope of the invention which is 
defined in the appended claims.