U.S. patent number 3,649,742 [Application Number 05/074,734] was granted by the patent office on 1972-03-14 for combined power and antenna cord for television sets.
Invention is credited to Pierre L. Tissot.
United States Patent |
3,649,742 |
Tissot |
March 14, 1972 |
COMBINED POWER AND ANTENNA CORD FOR TELEVISION SETS
Abstract
A power cord for a television set encompasses the antenna cable
in a single, molded unit. An exterior antenna cable terminates in a
capacitive coupling unit adjacent to the electrical power wall
outlet in the building such that when the power cord is plugged in,
the television antenna lead is automatically capacitively coupled
to the exterior antenna television cable. Permanent magnet means in
the outlet aid in holding the capacitive coupling in place.
Inventors: |
Tissot; Pierre L. (Pacific
Palisades, CA) |
Family
ID: |
22121358 |
Appl.
No.: |
05/074,734 |
Filed: |
September 23, 1970 |
Current U.S.
Class: |
174/70R; 174/66;
174/74R; 174/115; 333/24C; 335/219; 343/850; 343/905; 439/38;
439/279; 439/916; D13/138.1 |
Current CPC
Class: |
H01P
5/00 (20130101); Y10S 439/916 (20130101) |
Current International
Class: |
H01P
5/00 (20060101); H01q 001/50 (); H04b 001/00 ();
H01r 011/30 () |
Field of
Search: |
;174/53,55,56,7R,74R,115
;325/308,356 ;333/24C ;335/219 ;336/DIG.2
;339/12R,12G,28,59R,62,63R,12R,122R,123,147R,147P,195R
;343/850,905,906 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Askin; Laramie E.
Claims
What is claimed is:
1. A combined power and antenna cord for television sets
comprising, in combination:
a. power leads for connection to one end of the TV set and
terminating at their other ends in plug prongs;
b. a signal transmission line including two conductors for
connection at one end of the TV set and connecting respectively to
a central flat conducting disc and surrounding conducting washer;
and
c. an insulating plastic material molded about said power leads and
transmission line to define a single elongated integral cord, said
plastic material defining a plug body for said plug prongs and a
downwardly extending flexible flap within which are imbedded said
disc and surrounding washer, whereby capacitive coupling of TV
signals can be effected to said disc and washer.
2. The combination of claim 1, in which said two conductors are
defined by a coaxial cable.
3. The subject matter of claim 1, further including, in
combination, an electric wall outlet box for receiving said prongs;
conductive magnetic means incorporated in said electrical wall
outlet box having north and south poles for connection to a master
television antenna and coaxially arranged and terminating in flat
surfaces positioned and dimensioned to be substantially opposed to
and congruent with said disc and surrounding washer in said flap
when said prongs are received in said box so that capacitive
coupling is retained by magnetic attraction of said disc and
surrounding washer to said poles respectively.
4. The subject matter of claim 3, in which said electrical outlet
box includes a removable cover plate, said magnetic means being
incorporated in said cover plate.
5. The subject matter of claim 3, in which a portion of said cord
extends away from said plug body and flexible flap at an
intermediate point such that pulling on said cord will exert a
substantially equal force on said prongs and flap to facilitate
separation from said outlet box.
6. An integral elongated plastic material defining a flexible cord;
and a signal transmission line including two conductors imbedded in
said cord, said conductors at one end of the cord connecting
respectively to a central flat metallic disc and surrounding flat
metallic washer, the said one end of the cord completely imbedding
said disc and washer whereby signals may be capacitively coupled
from said transmission line through said one end of said cord
without exposure of any metallic portions of said transmission
line.
7. The subject matter of claim 6, in which said two conductors are
defined by a coaxial cable.
8. The subject matter of claim 7, further including power leads
imbedded in said plastic material whereby said flexible cord may be
utilized to transmit both power and signal energy to a television
set.
Description
BACKGROUND OF THE INVENTION
The use of antenna leads on television receivers is cumbersome and
a great source of difficulties, particularly when sets have to be
moved from room to room. Who has not, at one time or another,
fumbled with the primitive "two-screw/twin-lead" arrangement on the
back of a television receiver with frazzled-out, stiff and brittle
steel wire ends ? Coaxial screw connectors are an improvement but
bring new problems with the need for a dangling accessory on the
back of the television receiver. On the fragile antenna terminal
screws hangs suspended the fairly heavy combination of a
transformer with the attached coaxial cable, resulting in
frequently ripped-out coaxial screw connectors. Attaching coaxial
connectors requires know-how, it requires the right size connector
and, further, the right-sized crimp-ring matching the particular
cable size used. Finally, one needs a special crimping tool. All of
this procedure is essentially impossible for the layman.
A vast field of plugs and connectors all have one common ailment:
one hefty yank on the antenna cord results in a severed connection,
needing professional repairs. Frequently a television benchman is
faced with the arduous task of finding and removing a hairlike bit
of steel strand that fell off a "birds-nest-style" antenna
connection down into the chassis wiring, creating havoc.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
My invention does away with all this by doing away with a
conventional antenna cord even though an outside- (or master-)
antenna is used. Sets are simply plugged into the nearest
electrical wall outlet not necessitating any further thought since
this act accomplishes all that is needed. Proposed is the use of a
fairly lightweight, 8 foot long, flexible, rugged, seamless,
plastic cord with a molded-on, indestructible, polarized male
powerplug; in essence, a combination coaxial antenna cable and
power cord. Power companies and underwriters should welcome this
design, even though added code regulations might have to be sought,
permitting my cord.
With the foregoing arrangement, television receivers can easily be
moved from room to room by otherwise incompetent help resulting in
a tremendous boon in the hotel-motel field. Anyone, having enough
wits to plug in a lamp, can be sent to correctly install a
television-receiver equipped with my cord. A less obvious but great
advantage of my invention is the fact that a strong tug either cord
or plug will merely dislodge the plug from the wall outlet with no
harm done. Both light and sound on the television receiver will go
out. Thus, a "yanked" cord will teach the user to plug it in again,
thereby restoring perfect reception. On the other hand, with one
lead-in-wire broken off one antenna terminal (or even with both
gone) people have been known to suffer with "snow" and intermittent
color for months, never suspecting simple lead-in-wire troubles and
shying away from the expense involved in calling a television
serviceman.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention as well as various further
features and modifications thereof will be had by now referring to
the accompanying drawings in which:
FIG. 1 is a perspective view of a television set using my new power
cord in accord with the invention;
FIG. 2 is a cross section of the power cord taken in the direction
of the arrows 2--2 of FIG. 1;
FIG. 3 is a stripped away elevational view of the various
components making up the power cord of FIG. 1;
FIG. 4 is a side elevational view of the plugged body portion of
the power cord;
FIG. 5 is an "X-ray" front view of the plugged body of FIG. 4;
FIG. 6 is a perspective view of a modified electrical outlet
box;
FIG. 7 is a front elevational view of a cover plate for the box of
FIG. 6;
FIG. 8 is a front view of part of the internal mechanism
incorporated in the control box;
FIG. 9 is a view partly in cross section of the component of FIG. 8
in mating relationship with a portion of the plug of FIG. 4;
FIG. 10 is a perspective view of a terminal unit affixed to the
inside cover of the TV set for the cord 10 of FIG. 1;
FIG. 11 shows a corresponding mating unit incorporated in the TV
for cooperation with the unit of FIG. 10;
FIG. 12 is a front partial perspective view of a modified unit for
use with a conventional electrical outlet;
FIG. 13 is a side elevational view of the structure of FIG. 12;
FIG. 14 is a perspective view of a connector without powerlines in
accord with the invention;
FIG. 15 is a side elevational view of an extension cord for an
antenna lead-in in accord with the invention;
FIG. 16 illustrates certain terminal board portions of a TV
set;
FIG. 17 illustrates a modified plug usable with conventional TV
sets; and,
FIG. 18 illustrates certain internal connections in the unit of
FIG. 17.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 to 3, there is shown a TV set with an oval
cable 10 comprised of a molded vinyl jacket with two imbedded,
stranded copper conductors 11. Below is a thin plastic sleeve 12
which surrounds a shielding copper braid 13 as shown in FIG. 2.
Inside braid 13 is lightweight, plastic foam 14 and finally in the
center of foam 14 is a thin copper conductor 15, also stranded.
FIG. 3 clarifies the makeup of this cable in a cutaway view and an
8-foot section is fastened in manufacturing onto the back cover of
the TV set. This later phase will be presently covered.
The end of the cable 10 as shown in FIG. 1 terminates basically in
a standard male powerplug body 16 with molded-in, nonreversible
power blades 17 and 18 firmly imbedded in the vinyl body. Blade 18
of course is wider than blade 17. Also molded onto body 16 is a
seemingly useless, down-hanging thin flap 19, also made out of
vinyl.
The side view FIG. 4 shows that the flap 19 also possesses a thin
layer 20 which will face the wall having an electrical outlet. Flap
19 has a certain "give" or flexibility. The purpose of layer 20
shall be explained presently. It shall be noted, however, that it
is an insulating material. 16, 19, and 20 all form one molded unit
and molded together with the cord of FIG. 1. Power wires 11 are of
course anchored onto power blades 17 and 18 inside plastic body
16.
Referring now to FIG. 5, this drawing can be considered an "X-ray
view" of flap 19. Revealed are two soft iron sheet metal stampings
imbedded in the plastic, one, a large washer 21 which has been
fastened electrically and mechanically onto braid 13, preferably by
soldering. Concentrically arranged to 21 is disc 22 onto which core
15 has been soldered. But neither side of flap 19 has any visible
contacts, a very important feature of my invention. Discernible in
FIG. 5 is also sleeve 12 leading away into the power cord.
FIG. 6 shows a basically standard electrical wall outlet box made
out of steel, commonly referred to as "plaster-box" but designed
here with two compartments. The large section 23 is the equivalent
to a "two-outlet" "plaster-box" for standard electrical use,
several being found in almost any room of almost any home. Small
section 24 adjacent below and separated by a solid steel wall 25
has been provided for coaxial cable termination, totally
independent from the electrical section 23. Shown at 26 are the
familiar, partially stamped-out openings. Significantly the
customary bottom one in steel wall 25 is now missing. Section 24
carries three such cutouts shown at 27 thru one of which the
installer brings in the coaxial antenna cable arriving from the
antenna amplifier in the building. This phase will be covered in
more detail presently.
In FIG. 7 we see an ivory colored plastic cover plate to deck the
"plaster-box" shown in FIG. 6. There are two of the familiar,
semiround openings 28 accepting traditional plastic, electrical
inserts such as: outlets, switches, pushbuttons, signal lamps and
others. The larger round bottom opening 29 has been provided to
accommodate the part according to FIG. 8, showing a soft green thru
said opening 29.
FIG. 8 shows a circular, shallow, plastic body 30 with a front
protrusion, the latter decked with a thin outermost layer 31. Layer
31 is the actual active, circular front area, shouldering neatly
into opening 29 to produce a flush fit with the cover plate shown
in FIG. 7. The eye perceives then a soft green area in lieu of an
insert at opening 29 without any holes, slots or contacts. Layer 31
is identical in nature to layer 20 and it will be explained in more
detail presently. 36 is a molded-in coaxial male screw connector, a
standard part in the coaxial cabling industry.
FIG. 9 shows an enlarged internal side view of the body 30 shown
first in FIG. 8, whereby 32 represents a shallow but powerful pot
magnet, similar to those used in the loudspeaker industry. But here
the customary, cylindrical center pole piece breaks down into two
different sections, 33 and 34. The rim of the pot magnet 32 is a
magnetic north pole, the two centerpieces 33 and 34 together form
the opposing magnetic south pole. 34 is made out of the same
magnet-steel as 32. Section 33, shown dotted in FIG. 9, is also a
permanent magnet, but it does not conduct electricity. Magnets with
this feature are well known in the art under such names as
"flexible magnetic strip" etc. A short piece of insulated copper
wire 35 has been soldered onto magnet 34, which of course conducts
electricity, and the other end of wire 35 is soldered onto the
center terminal of the plastic imbedded, male coaxial connector 36.
The outer threads of connector 36 have a soldered-on short piece of
insulated copper wire 37. The other end of wire 37 has been
soldered onto pot magnet 32 which of course also conducts
electricity. Female screw connector 38 with its attached coaxial
cable 39 establishes the connection to the antenna amplifier in the
building. Body 30, shown in both FIGS. 8 and 9, can be rotated into
one of three positions so as to make connector 36 face the most
desirable one of the three cutouts 27 once body 30 sits inside
compartment 24 of the "plaster-box" shown in FIG. 6. In FIG. 4 with
20, in FIG. 8 with 31 and in FIG. 9 again with both 31 and 20 are
shown thin layers of a soft green colored, filmlike material with
high dielectric properties but being an electrical insulator. Thin
films with high dielectricity are well known in the art of making
ceramic capacitors. Film 31 has been bonded onto the front
protrusion of 30 and also onto pot magnet rim 32 and south pole 34
whereas film 20 has been bonded onto soft iron stampings 21 and 22
and of course also onto the encasing vinyl flap 19.
The powerplug described in FIGS. 1 to 4 is inserted now into the
lower one of the two electrical outlets 28 in FIG. 7 which is only
possible in such a way, that the down-hanging flap 19 mates with
disc area 31 in FIG. 7. In practice this happens with a soft, but
positive "tap" whereby any slight misalignment is automatically
compensated for by the resiliency of flap 19. Referring again to
FIG. 9, it can be seen, that the magnetic flux from the north pole
32 finds an easy path into washer 21, hence over the small plastic
gap into disc 22 and back into the south pole formed by 34 and 33.
The resulting magnetic pull keeps flap 19 snugly against the front
protrusion of body 30. The two layers, 20 and 21, being only paper
thick, pose little hindrance to the magnetic flux.
A very significant feature of my invention is the fact that I do
not have to rely on any intimate (galvanic), metallic touch with
all inherent problems such as loose, corroded, dirty, bent, damaged
or even lacking (broken-off) contacts. The radiofrequency signal
transfer takes place by capacitive action through the two
intervening layers of plastic film: 31 and 20 in FIG. 9. In effect,
the whole arrangement is nothing electrically but two small
capacitors linking core with core and braid with braid from the
coaxial cable 39 in the wall of the building over to the coaxial
cable 12, 13, 14 and 15 in the power cord, as can be seen by
studying the FIGS. 4, 5, and 9. A very significant feature of my
invention is the fact that washer 21 and pot magnet 32 both
together form a logical continuation of the shielding (static
preventing) qualities of both braids of both coaxial cables, the
one in the building and the one in the power cord. This can readily
be appreciated by observing how "hot" 34 and 22 are nested within
radio-electrically "grounded" metals. Of course there will be a
slight loss in the signal transfer, easily born by the antenna
amplifier in the building. As already mentioned above, as seen in
FIG. 9, coaxial cable 39 terminates at screw connector 38 and is
brought through one of the cutouts 27 to be screwed onto connector
36.
Insertion of the powerplug of FIG. 1 into the topmost of the two
power outlets 28 in FIG. 7 is illogical, though utterly harmless:
the only result is no television reception and obstructed bottom
power outlet 28. Rather, the identically soft green colored
plastics of both flap 19 and dot area 31 will guide the user to
avail himself of the bottom outlet 28 for television use. Insertion
of the plug with flap 19 sticking upwards of course is rendered
impossible by the polarization feature of both plug and power
outlets 28 in FIG. 7. Power companies retain their absolute
priority in the intended use of their outlets. Any electricity
consuming device can of course be inserted as always in either one
of the two power outlets 28 in FIG. 7.
Analyzing the side view in FIG. 4 reveals that the power cord 10 is
not placed in the same line as the power blades 17 and 18. This has
been done in order to accomplish a clean mechanical separation,
should the cord 10 be "yanked." In such a case the magnetically
held-on flap 19 will get a share of the tug. Contemplating my
design one might wonder where the customary coaxial matching
transformer is to be found, a standard piece of equipment between
the wall and television wherever coaxial cable is used. As will be
explained later, the coaxial matching transformer will be relegated
into the interior of the television receiver, in close proximity of
the tuner. Doing away with such a vulnerable "outboard" item is
very desirable.
FIG. 10 shows how the power cord shown in FIG. 1 is terminated at
the inside of the back cover of the TV equipped with my power cord.
Use has been made of the standardized "two-hole," female, plastic,
"interlock" shown striped with 41. With 42 and 43 the recessed
ferrules are denoted onto which power wires 11 are fastened as they
arrive out of power cord 10. In my design the original body 41,
shown striped, has been enlarged and is riveted onto the television
back cover by the three rivets 44, 45, and 46, the enlarged body is
shown not striped. It shall be noted here, that the accepted
mounting fashion of "interlocks" is the two-point suspension with
rivets at 44 and 45. In my design three rivets are used in
triangular fashion, the third one being shown with 46. The body
encompasses a molded-in, standard, coaxial, "pushon" male connector
for low energy radiofrequency signal transfer with center male pin
47 and "spring-tensioned," surrounding steel jacket 48. Core 15
from power cord is soldered onto male pin 47 and braid 13 is
soldered onto steel jacket 48.
FIG. 11 shows the matching counterpart to FIG. 10 as it is riveted
onto the rear apron of a television receiver embodying my power
cord. Here again the "old-fashioned" male interlock is shown
striped. Three-point riveting at 49, 50, and 51 insures rigidity.
Male pins 52 and 53 lead to the power section of the television
receiver. Center female ferrule 54 is soldered to the core of a
section of coaxial cable leading to the tuner of the television
whereas the steel rim 55 of the female coaxial connector is
soldered to the braid of the same section of coaxial cable leading
to the tuner of the television receiver. Since self-explanatory and
beyond the scope of this invention, the internal wiring of the TV
has not been shown. It is obvious, that while accepting pins 52 and
53 into ferrules 42 and 43, simultaneously a "pushon" connection is
established between the two coaxial connectors as pin 47 will enter
ferrule 54 and jacket 48 will slip over steel rim 55.
Standard and basic safety requirements are met by the foregoing
arrangement. A "do-it-yourselfer" disrupts power going to the set
in the process of removing the back cover of a television receiver
equipped with my power cord. More, now with my design, the signal
transfer also is uncoupled. Thus, my invention overcomes a present
day difficulty. In order to service a television receiver antenna
wires have to be unscrewed, matching coaxial transformers have to
be removed (if used) and in addition, often so-called "VHF-UHF
band-splitters" have to be removed until finally the back cover can
be loosened. My power cord design avoids all this elegantly with a
clean plug/unplug separation. "Splitter-networks" and matching
transformers are built together with the tuner, a vast improvement
from all aspects. At the present time, some high-class television
receivers already incorporate internal matching transformers for
coaxial cabling; this principle is known and of course no claims to
novelty are made regarding this detail. Thus, plug 16 of FIG. 1
with the cable 10 and end unit of FIG. 10 together form one sleek,
8 foot long (legal length) subassembly, ready to be riveted onto
the back cover of a television receiver during factory
production.
While the outlet box according to FIG. 6 leads to a very neat
subsurface installation, in existing buildings the required
electrical work in most instances will rule out adaptation of said
outlet box. Therefore, a modification of the part shown with FIG. 8
has been worked out, the scope being circumvention of the
molestation of the electrical outlet box as such. Little or no code
modification will have to be sought since now we have a
surface-mounted feeder cable not entering the outlet box at all.
The part shown with the FIGS. 12 and 13 is electrically the same as
the one shown with the FIGS. 8 and 9 and there is very great
mechanical similarity. The only actual difference being the fact,
that the active, "signal-giving" part has been lifted out of the
wall. Therefore, only a brief explanation shall follow.
Plastic outlet cover plate 56 is conventional with its two outlet
holes 28 for power but thickens below into a desklike configuration
embodying again part 30 shown in the FIGS. 8 and 9. Discernible on
the front is green dot area 31 and male connector 36. New is the
fact that the wall-facing area, which extends beyond the length of
an ordinary cover plate, has been adhesive covered by 57 and the
adhesive has been paper protected by 58 during manufacturing. This
has been done as an assist to the existing and customary single,
center mounting screw 59. Adaptation is simple: screw 59 is
loosened and the old cover plate is discarded. The new cover plate
56 is applied and checked for snug fit at the wall opposite 57 and
58. Next paper 58 is peeled off and plate 56 secured with screw 59.
As with FIG. 9, screw connector 36 accepts female connector 38 and
the coaxial cable 39, now obviously surface mounted, leads to the
antenna amplifier in the building. Flap 19 for the plug shown in
FIG. 1 easily bends away the few degrees needed to mate with dot
area 31 as the plug is inserted into the lower one of the two
receptacles 28. Neither the electrical house wiring nor the
"plaster-box" need to be touched other than switching cover plates.
For the latter function a licensed electrician is not required.
If one removes the power wires 11 from the cable of FIGS. 1, 2, and
3 then one arrives at a configuration according to the FIG. 14.
Very significantly, here are no contacts at all, the plug assumes a
podlike appearance. A flexible coaxial cable has been molded into
the pod and of course terminates at the internal pole pieces, not
specifically shown in FIG. 14 since self-explanatory with the
foregoing text. The magnetic counterpieces, the pot magnet assembly
is contained in the electronic apparatus indicated to the left
which does not have to be a television receiver. The podlike "plug"
neatly fits into a circular depression in a "self-aligning"
fashion, even rotation is possible, i.e., the coaxial cable can
lead away in any radial direction. If the touching surfaces are
designed to withstand friction, one arrives at a coaxial magnetic
coupler being held on magnetically onto the center of a piece of
rotating machinery.
FIG. 15 shows the concept of an extension cord for coaxial cable
use. Again there are no visible contacts so that it is a child- and
foolproof linkup. The item has been shown "plugged into itself" in
FIG. 15 to demonstrate the ease and simplicity of such connectors,
very particularly for underwater (marine) use or in outer space
where the absence of metals precludes corrosion problems or
"sticking together" of metal controls, as can occur in vacuums. Of
course one cable end carries the somewhat heavier pot magnet
assembly whereas the other cable end carries the lighter soft iron
pole pieces, all plastic imbedded. In FIG. 15 too, internal parts
are not shown since the construction has already been
explained.
Experimentation has shown that it is desirable to place the "heavy"
pot magnet assembly into the wall or into whatever stationary
machinery shall be chosen. The "light" parts, the iron stampings,
are placed into the generally movable plug end of the cable. Thus
in marine use, the magnet assembly would be in the hull or in outer
space use, in the side of a spaceship. However, the reversed
arrangement is feasible and the scope of my invention should not be
circumvented by a change of the relative positions of magnets and
pole pieces. Also different shaped magnets could be used, such as
laterally open U-shaped magnet; however, the proposed, closed pot
magnet assembly proved the best configuration.
The invention presented herewith adapts itself particularly well to
new construction, where all power outlets in a building can be
furnished and wired according to my system, and where they all are
fed from a central antenna amplifier. Television receivers equipped
with my power cord, will have to carry on their backs an antenna
terminal board according to FIG. 16. Since virtually all television
receivers manufactured already carry such a terminal board (of a
somewhat simpler nature), the added cost for my terminal board is
negligible. With 60 and 61 the actual tuner input connections are
denoted with standard 300 ohms twin lead termination. Onto these
screws "pigtails" 62 and 63 can be connected, they come out of the
back cover through opening 64 and are inside the television
fastened to rod aerials, so-called "rabbit-ears"; or, a roof aerial
being on hand, "pigtails" 62 and 63 are disconnected from terminals
60 and 61 and the roof aerial (in twin lead configuration) is
connected onto 60 and 61. All this is standard and accepted
procedure and only mentioned here to illustrate my particular
antenna terminal board wireup. In a building that has been wired up
according to my proposals, the connecting links 65 and 66 are
closed, i.e., connected onto respectively 60 and 61 and no wire is
now attached onto 60 and 61 since my power cord takes over.
What happens now inside the television receiver is shown within
FIG. 16. Swiveling links 65 and 66 are leading to a matching
transformer 67 whose secondary winding receives the antenna signal
from washer 21 and disc 22 through the coaxial cable 12, 13, 14,
and 15, the latter numbers being shown in detail in FIG. 3.
Thus, the three possible modes of television reception have been
described, namely:
a. indoor rod aerial reception,
b. roof aerial reception,
c. reception through my power cord.
Conversely, should an older television receiver be brought into a
modern building that has been wired up according to my proposals,
then an inexpensive adapter as per FIG. 17 comes into play.
Developed out of the powerplug shown in FIG. 1, here the cord as
such has been omitted. The soft green colored lower plastic plug
body 68 contains of course again body 30 shown in FIG. 9 and is
held on magnetically onto dot area 31 shown in FIG. 7, in the way
that has been covered repeatedly.
New in this version is a molded-in matching transformer 71,
establishing the proper connections according to FIG. 18. Either
300 ohm twin lead termination or 75 ohm coaxial cabling is selected
by the user. Top part 69 is a "feed-thru" plastic power outlet, in
this case solely needed for mechanical linkup, as can be readily
understood. In this case, the bottom one of the two grounding
ferrules 70 from the bottom outlet 28 in FIG. 7, that was not
mentioned before, is now available again past the "feed-thru"
device 68, it is denoted with 72. With the two above-described
devices, namely the terminal board in FIG. 16 and adapter in FIG.
17, full compatibility in the use of my power cord has been
achieved.
The power cord described herewith clearly upgrades present day
television installations by forcing the user to directly attach the
set to a wall outlet thus preventing the use of a so-called
"three-way plug." (Two "three-way plugs," connected in series and
hot to the touch have been encountered in homes. If really a
"three-way plug" has to be used due to a scarcity of available
outlets, then the user will automatically operate lower-powered
items (such as lamps) through such a "three-way plug," greatly
alleviating the unsafe conditions.
But the greatest fire hazard in homes is undoubtedly the overloaded
extension cord with an undersized copper cross section, the kind
readily available on the open market. Heavy loads are often times
operated through such a flimsy "lamp-cord." Such a cord, stapled to
a wooden baseboard, presents an explosive situation. Now, the one
high wattage item in nearly constant use in homes is the large
color television but with my power cord no longer functional
through an extension cord. By these considerations, power companies
and underwriters should welcome my design and the general use
should be made mandatory over a period of time.
* * * * *