Electrical power take-off unit for cigarette lighter socket of vehicle

An electrical power take-off unit which includes an adaptor for insertion into the cigarette lighter socket of a vehicle wherein the adaptor has means for tapping off electrical power from the electrical terminals in the socket so as to be able to supply electrical power to accessories, such as calculators, clocks, computers and the like, carried in the vehicle. The adaptor may be provided with a socket itself for receiving the cigarette lighter. Means can also be provided on the adaptor to directly mount an accessory, such as a digital clock, thereon. The adaptor can also be used even when an accessory is mounted directly on the instrument panel of a vehicle. In such a case, electrical conductors extending from the adaptor to the accessory can be concealed in a decorous manner.

This invention relates to improvements in the use of cigarette lighters in 
vehicles and, more particularly, to an improved adaptor for tapping off 
electrical power supplied to the socket of such a cigarette lighter. 
BACKGROUND OF THE INVENTION 
Most passenger vehicles and many other types of motor vehicles have a cigar 
or cigarette lighter unit installed on the instrument panel or dashboard 
as standard equipment. Such unit includes a fixedly mounted socket and a 
lighter member which is removably received in the socket. The size and 
shape of the socket and lighter member are standarized in vehicles 
manufactured in the United States. 
Tyically, such a lighter unit is not used as a means of supplying 
electrical power to electrical and electronic accessories on the 
instrument panel or at other locations in the vehicle itself. This is 
probably due to the fact that such use prevents ready access to the 
lighter function in that it would prevent use of the lighter member. Also, 
the socket of the lighter unit is not used as means for mounting accessory 
devices or equipment. This latter drawback is probably due to the fact 
that the size of the accessories which might be mounted prohibits such 
use. Also, such mounting would prevent the use of the lighter function. 
Furthermore, accessories, such as lamps or the like, which do use the 
lighter socket for electrical power do not require continuous power to be 
effective as do electronic devices having memories, such as calculators, 
clocks, computers and the like. 
Thus, in view of the foregoing, there is a need for a convenient source of 
electrical power for electronic and electrical accessories in a vehicle, 
which accessories augment the factory-supplied information and comfort 
devices on the instrument panel and in the general area of the driver of 
the vehicle. By a convenient source is meant such a source which requires 
no special skills or significant effort to use or install in place. To 
provide such a convenient source of electric power for memory-based 
devices, such as clocks, calculators, computers and the like, the 
following criteria should be satisfied to provide acceptance by a wide 
audience of vehicle drivers: 
1. There must be a suitable mounting place for the accessory, one which 
does not detract from the decor of the instrument panel or the interior of 
the vehicle and one which does not block the view of other accessories 
near the driver; 
2. The cigarette lighter capability must be retained if possible although 
the fact that more and more people are non-smokers or are becoming so 
permits the elimination of the lighter capability in certain cases; 
3. The power source must be readily installable in a cigarette lighter 
socket by persons without special skills or who are not mechanically 
inclined; 
4. The power source should be secured against theft even if it requires 
extra cost. 
SUMMARY OF THE INVENTION 
The present invention provides an improved structure for satisfying all of 
the aforesaid criteria. To this end, the invention provides an extender or 
adaptor for insertion into the socket of a conventional cigarette lighter 
unit of a vehicle and the adaptor has means for tapping off and supplying 
electrical power on a continuous basis for use by accessories, such as 
calculators, clocks, computers and the like, all of which are memory-based 
and generally require electrical power continuously. The adaptor is 
preferably provided with means for locking the same into the socket to 
prevent theft and unauthorized removal therefrom. The adaptor may be 
provided with a socket itself for receiving the conventional cigarette 
lighter member, whereby the ligher capability of the cigarette lighter 
unit can be retained. This latter feature is optional as desired if, for 
instance, the vehicle driver is a non-smoker or does not wish to encourage 
his passengers to smoke while in the vehicle. 
In one embodiment, the adaptor has an electrical power tap-off provided for 
supplying electrical power to an accessory remotely from the adaptor 
itself. To this end, the accessory can be mounted on the instrument panel 
in a suitable location, such as an accessory cut-out initially provided in 
the instrument panel. A decorous covering can be provided between the 
adaptor and the accessory to mask the electrical leads therebetween. 
In another embodiment, the adaptor is provided with means for mounting an 
accessory directly to the adaptor itself. Such mounting means can include 
a rigid or pivotally mounted arm, a gooseneck extension, or other such 
connecting means. The mounting can be such that the accessory is directly 
viewable by the vehicle driver or occupant without interfering with the 
view of other accessories on the instrument panel. 
The primary object of this invention is to provide an improved electrical 
power source for the interior of a vehicle having a conventional cigarette 
lighter unit wherein the source comprises an adaptor insertable into the 
socket of the lighter unit with the adaptor having means for tapping off 
electrical power therefrom so that one or more electrical or electronic 
accessory can be mounted either on the instrument panel of the vehicle or 
directly on the adaptor itself and the accessories can be continuously 
supplied with electrical power to thereby permit the vehicle driver to 
utilize calculators, clocks, computers and the like while operating his 
vehicle. 
Another object of this invention is to provide a power source as described 
wherein the adaptor can be provided with a socket for receiving the 
conventional cigarette lighter unit to allow the vehicle driver and 
passengers to have access to the lighter capability of the lighter unit 
notwithstanding the continuous presence of the adaptor which supplies 
continuous electrical power to one or more accessories requiring such 
continuous electrical power. 
A further object of this invention is to provide a power source as set 
forth above wherein the adaptor is easily installed even by those with 
little or no mechanical skills yet the adaptor can be secured in place to 
prevent theft or unauthorized removal thereof from the lighter socket. 
Still another object of this invention is to provide an improved electrical 
power source of the type described wherein the source includes an adaptor 
which does not detract from the decor of the instrument panel and can be 
used with accessories spaced a distance from the lighter socket in a 
manner to mask any electrical connections extending between the adaptor 
and the accessories. 
Other objects of this invention will become apparent as the following 
specification progresses, reference being had to the accompanying drawing 
for an illustration of several embodiments of the invention.

The first embodiment of the power source of the present invention is 
illustrated in FIG. 1 and includes an extender or adaptor 10 having a 
first cylindrical part 12 for insertion into the tubular, cylindrical 
socket 13 of a standard cigarette lighter unit 15 mounted at any suitable 
location in the instrument panel 17 of a vehicle. Adaptor 10 further 
includes a second cylindrical part 14 integral with part 12 but having a 
greater diameter than the latter. Parts 12 and 14 are of electrically 
insulating material. Part 12 has one or more spring-out retainers 16 which 
snap out and extend into corresponding slots 18 in socket 13 when part 12 
is fully inserted into socket 13. When adaptor 10 is pulled outwardly of 
the socket, retainer 16 is cammed into a recess 19 formed in part 12, 
thereby permitting removal of adaptor 10 from the socket. 
The retainers can be releasably locked or held in notches 18 by respective 
pins 20 which extend through corresponding holes or passages 21 in adaptor 
10. Such a passage 21 is shown in dashed lines in FIG. 1. The hole extends 
longitudinally of the adaptor and is slanted to its central axis. Thus, 
the corresponding pin 20 can be put in or taken out from the side of part 
14 near its outer end. 
After one or more pins 20 are in place, adaptor 10 cannot be removed from 
the socket. This assures against theft and unauthorized removal of the 
adaptor. The pins are designed so that only a special tool can remove them 
to release adaptor 10 from socket 13. 
Instead of using retainers 16, which project into slots 18 of socket 13, 
spring retainers (not shown) could be used which move into frictional 
engagement with the inner surface of socket 13. A tapered pin would be 
provided in each hole 21, which pin would be rotatable to cam the 
corresponding retainer into frictional engagement to the inner surface of 
the socket. 
The socket has an electrical terminal 22 to which a lead 24 is connected, 
lead 24 being coupled to the battery of the vehicle. Terminal 22 is 
engageable by a metallic plug 26 carried by part 12 in a central passage 
28 therethrough. A second plug 30 at the opposite end of the passage makes 
electrical contact with a conductor 32 which extends laterally of the 
passage and terminates at the outer periphery of part 14. A cable 34 makes 
electrical contact with lead 32 and extends away from adaptor 10. Cable 34 
provides the power take-off means to an accessory (not shown in FIG. 1) 
spaced from the adaptor. 
Cable 34, as shown in FIG. 1, is premanently attached to conductor 32. In 
the alternative, a socket electrically coupled to conductor 32 can be 
provided near the outer periphery of part 14 for receiving a terminal pin 
on one end of cable 34. Thus, the cable can be separated from adaptor 10. 
Moreover, more than one conductor 32 may be provided for supplying 
electrical power by way of respective cables 34 to several accessories 
spaced from adaptor 10. Also, there may be several different pin-receiving 
sockets coupled to respective leads 32 in lieu of permanently connecting 
cables 34 to respective conductors 32, the sockets being spaced about the 
periphery of part 14. 
Part 14 may be provided, if desired, with an open-end, cylindrical recess 
36 for receiving the conventional cigarette lighter member 38, the one 
ordinarily receivable in socket 13. If constructed in this manner, adaptor 
10 can supply continuous electrical power to one or more accessories 
spaced from the adaptor yet the user of the adaptor still has the 
cigarette lighter capability afforded by the presence of lighter member 
38. The lighter member has a cylindrical portion 40 insertable within 
recess 36, portion 40 having the usual frictional retaining means to 
releasably hold it in recess 36. 
Adaptor 10 may be used with any one of a number of different accessories, 
such as calculators, clocks, computers and the like, which may or may not 
be memory-based and which may or may not require a continuous supply of 
electrical power. A typical application of adaptor 10 is shown in FIGS. 3 
and 4 wherein a digital clock 42 is utilized at a location spaced from 
lighter socket 13 on the instrument panel 17 of a vehicle. Clock 42 is 
located at a cut-out 46 initially provided in the instrument panel when 
the latter is manufactured. A suitable holder 48 having a back 50 is 
secured by an adhesive 51 to the front surface of the cut-out as shown in 
FIG. 4. Holder 48 further includes a pair of spaced, front parts 52 (FIG. 
3) disposed forwardly of and spaced from back 50. Clock 42 is placeable in 
holder 48 in the region between back 50 and front parts 52 as shown in 
FIG. 4. Cable 34 extends from adaptor 10, along the undersurface 54 of the 
instrument panel, then up the front face of the instrument panel to clock 
42 as shown in FIGS. 3 and 4. To preserve the decor of the instrument 
panel, a low-cost plastic mount of a tape-like construction having a 
self-adhesive backing can be provided for this purpose. An adhesive 
plastic conduit 56 runs down the front of the instrument panel and is 
split to accept power cable 34. These low-cost plastic pieces can be 
produced and stocked for all popular car models, thereby permitting 
electronic accessories to be standardized for various vehicle 
configurations. 
Another embodiment of the extender is shown in FIG. 2 and is denoted by the 
numeral 110. Adaptor 110 is substantially the same in construction as 
adaptor 10 except that adaptor 110 has an enlarged, outer part 114 to 
which an accessory 116 can be mounted directly. For purposes of 
illustration, accessory 116 comprises a digital clock mounted on the outer 
end of an arm 118 which is secured to part 114 in any suitable manner. 
Again, for purposes of illustration, arm 118 is integral with a ball 120 
pivotally mounted in a spherical recess 122 in part 114 so as to provide a 
ball-joint connection between the arm and the part. In lieu of the 
presence of ball 120, arm 118 can be rigidly connected to part 114 or 
other variations can be provided, such as a gooseneck extension. This 
allows manipulation of the accessory to permit it to be oriented for 
optimum viewing as determined by the vehicle driver or an occupant of the 
vehicle. The electrical connections to the clock can be made by way of a 
first cable 123 extending through arm 118, ball 120 and part 114 to a 
first plug 125 electrically coupled to a second plug 127 in a central 
passage in the inner part 113 of adaptor 110, part 113 being insertable 
within a socket 115 which is substantially the same in all respects as 
socket 13 of FIG. 1. 
Many vehicles will have insufficient room for the use of the ball-joint 
feature of adaptor 110 and some may not even be able to accommodate even 
the adaptor. In most cases, the electronic accessories will have a display 
and will require a line-of-sight position with respect to the vehicle 
driver. This is facilitated by the ball-joint connection. However, it may 
not be necessary for many vehicles since the lighter socket is usually 
designed to be in plain view and hence the simple direct plug-in accessory 
of FIG. 1 with the accessory mounted directly on part 114 can be used. 
Thus, as in the FIG. 2 embodiment, the accessory would be both powered and 
supported by the adaptor; again, the adaptor may or may not have the 
lighter capability inasmuch as lighter member 138 can be eliminated if 
desired. Adaptor 110 will be locked in place in the socket in any suitable 
manner, such as described above with respect to the embodiment of FIG. 1. 
While the foregoing description has been made with respect to the mounting 
of the cigarette lighter unit on the instrument panel of a vehicle, it is 
to be understood that these lighter units can be mounted in a vehicle door 
or on an armrest in the vehicle. Also, locking means other than that 
described above can be used to releasably lock the adaptor in the lighter 
socket.