DE1936780A1 - Heating device in combination with an antenna device - Google Patents

Description

PATENT LAWYER IQU

DIPL-ING.

HELMUT GDRTZ

6 Frankfurt am Main 70 Schneckenhofsfr. 27 - Tel. 61 70 79

,. 18th July 1969

Gzu / Ra.

PPG Industries, Inc., Pittsburgh, Pennsylvania / U.S.A.

Heating device in combination with an antenna device

The present invention relates to the combination of one Antenna and a heater. The subject described here in particular when used in motor vehicle windows can also can be used in other systems where an object is required that fulfills the dual function of heating and antenna.

Heating circuits are known in the windows of automobiles or airplanes in order to remove deposits or icing that have formed on the surfaces of the windows. If the window is made up of layers, the circuit will have heating wires carried through an intermediate thermoplastic layer. The heating wires extend between a pair of busbars which are arranged along opposite side edges of the area of a pane to be heated. When an electric current runs through the wires ¹ , the area is heated and thus any moisture or ice film on the surface is removed. It is also possible to have a transparent _. ·. electrically conductive film on one of the transparent surfaces

00 9 8 097106 4

■ '■' ■■ '■■ ■ "...:''■■■■■■■' ■ '■ - ² -''■■■■' · ■■ - - ■ / · ■ ■ ' ■ '"· .-

to attach and use a current flowing through this film runs through it and heats the surface for the same purpose.

Monolithic glass or transparent ones suitable for window panes Plastic disks were used as surfaces for the bracket electrically conductive heating circuits are used. For example, wur-JL de a pair of busbars that are connected by either Heating elements arranged at a distance, such as metal-ceramic lines, applied to a glass surface or through electrically conductive metal oxide coatings that pass through. pyrolyte Decomposition of a metal salt formed on a heated glass surface, used as heating circuits on panes of glass. in the Vacuum deposited metal coatings and the like have been applied Glass and transparent plastic panels used.

It is also known to embed a wire or series of wires w or other conductive elements in the interlayer or on the surface of the panes forming a laminated windshield of an automobile or aircraft and to connect them to a radio antenna circuit of a vehicle radio so that an antenna is provided was. Prior to this invention, however, no attempt was made to use the same elements as were used for a heating circuit for a second purpose, namely an antenna. The reasons for this are obviously electrical problems. Radio waves received by an antenna must be effectively shielded from earth. Of the '

0090 097 1064

The heating circuit of an automobile or an airplane uses the Vehicle body as earth * A conventional heating circuit that uses the Vehicle body would therefore be used ale rope of the circle ground the antenna and the reception of the signals to a radio circuit impede.

According to one embodiment of the invention, the means used in the battery-operated heating circuit to isolate the high-frequency radio signals from earth is provided as a means with a high impedance for alternating current at radio frequencies and a low resistance for direct current for the heating circuit m. used by a separate earth or counterpoint earth for the radio, which _; electrically isolated from the battery earth; ; is . , \

Taking into account the obvious difficulties with a circuit carried by a window and serving both purposes, the present invention provides a means of isolating the high-frequency radio signals from the F-year . It also allows the passage of direct current from the automobile battery if so desired without affecting the high frequency alternating current signal. and vice versa. .

Ο09ΒΌ9 / 106Α

Further features, advantages and possible uses of the new invention "emerge from the" accompanying illustrations of exemplary embodiments as well as from the following description,

- It. demonstrate: -

Figure "1 is a schematic of a typical Sehaltdiagramm" h electrical circuit according to the invention,

2 shows the overall view of a monolithic pane of glass, used as the curved rear window of an automobile, with the electrical circuit directly is worn on a glass surface of the rear window,

Fig. 3 is a section along the lines "III-JII of Fig. 2 *

Fig. 4 is an overall view of an alternative leader game of the present invention, the Sehaltkreis through the intermediate layer one in layers

built glass plastic assembly, which is typical of an automobile windshield,

FIG. 5 is an enlarged partial section of part of the layered windshield of FIG. 4 * which shows how the heating wires forming part of the electrical circuit are embedded in the interlayer of the laminated windshield, - ■ - ■■■■■

00980971064

6 is an enlarged view taken along lines VI-VI of FIG Ed. 4,

Pig. 7 is an enlarged end view taken along lines VII-VII of FIG.

8 is a schematic diagram showing the usage a heater-stove combination in a vehicle " shows ν that is provided with an AM ^ FM-ladio, and,

Fig. 9 is a housing diagram; one example electrical circuit according to another. Embodiment of the invention.

In Fig. 1, an electrical circuit 11 is shown. the Circuit includes a battery 12, a switch 13, a pair of low-resistance direct current coils 14 and 15, which are connected to one another by an electrically conductive element 16. The latter exhibits lines made of electrically conductive material.

A pair of bus bars 18 and 19 extend across opposite edges of the heating area "and are in electrical Contact with opposite ends of the made electrical Conductive material existing lines 16. In addition, forms a supply line 17 to a branch from the busbar 18 the radio receiver 20. ^

A lead wire 24 connects this bus bar 18 to one Connection point 25. An additional line 26- connects the busbar 19 to an additional connection point 27. The point 25 connects the line 24 with two wires, one of which is the antenna line 17 and the other with the Coil 14 and over the battery switch 13 with äem hot end the battery 12 is connected. The latter is grounded at its negative end · It is entirely possible to reverse the polarity of the battery 12, so that the battery switch 13 with the the negative terminal of the battery 12 allied-and the positive Connection of the battery is grounded.

To the radio antenna from earth (referred to as port'29) to isolate, the coils 14 and 15 are between both ends of the Antenna heating circuit 11 and connected to the earth. To achieve this, the coil 14 is at its end of the connected busbar 18 at the distal end. Laid earth, and the coil 18 is grounded at its end remote from the end of the connected busbar 19.

While the coils 14 and 15 have a very small direct current

have resistance, they have a large impedance for alternating current, especially at radio frequencies. The coils 14 and 15 thus act as high impedances and isolate the radio antenna current circuit from earth for the radio frequency signals.

'- ootao9 / ios4 ν;.

However, when the battery switch 13 is closed, the coils H and 15 provide a very low resistance to the direct current represents, which is in the heating wires 16 through the busbars 18 ■ and 19 arrives. This enables the circuit 11 to be used both as a radio antenna and as a heating circuit for removing moisture, such as precipitation or ice, from the Surface of a window is used. *

Since the electrical lines 16 and the busbars 18 and 19 are preferably made of ceramic silver material and the Feed wires 24 and 25 with a copper braid with much higher height

thermal expansion coefficient are provided as ceramic silver, it was found to be very favorable for the copper lead wires 24 and 25, while maintaining the distances 28 along the busbars, point-solder and pull out the copper wires Öhend loosely between the spaced solder points let so that the copper and ceramic silver are dependent expand or contract differently due to temperature fluctuations can. The temperature fluctuations result from the activity of the heating circuit. There is no stress on the bonds between the supply wires and the Busbars weakens. .

In commercial embodiments of the invention, e.g. Automobile rear locks or taillights will be the resistance and sheiz elements 16 and the busbars 18 and 19. *

009809/1064

a typical ceramic conductive coating material comprising a highly conductive metal powder, such as
Silver, and a sintered binder. Typical ceramic conductive coating compounds that can be used may have the following compositions:

Mixture I.

Part of PbO

Flake silver

Weight percent 7.5 1.0

¹ »5 70.0

French 01
(French Fat Oil) mixture component 12.5 ZJ Weight percent Turpentine ' fe in yerte iltes silver 7.5 72.6 PbO 9.3 SiO ₂ y ■■■; ; /; . .: ■.;:. ^ _: / 1.7 H ₂ O
Ethyl alcohol ■ 7.5

00980 9/1064

Mixture III

A typical commercial mixture consists of a mixture of 90% by weight of a ceramic sirber mixture which is sold under the trade name AB Silber by the O'Bommel! Company of Carnegie, Pennsylvania _r and a non-conductive mixture of metal oxide sold under the tradename K 736 Black by Ferro Corporation of Cleveland, Ohio.

The electrically conductive strips 16 form narrow lines of ' nearly 0.08 cm (1/32 inch) wide. The Samrael rails 18 and 19, the ends of the strips 16 extend transversely connecting rows with one. Approximately 1/4 inch (0.6 cm) wide. The silver ceramic mix is preferably done by scraping, lone applied to the strips .16 and the rails 18 'and 19 by means of a "sieving by means of a silk sieve" known process. This provides a 0.0013 cm (0.0005 inch) thick finish on one surface of a Automobile rear window or rear window created. ·

The material specifically described has an electrical resistance of Oj-35 ohms per inch (2.54 cm) across the electrical conductive strips 16, the collecting thus deposited nen 18 and 19 an electrical resistance of 0.04 ohm per 2.54 om (per inch). If that with such a

Ö09Ö09 / 1064

.- ■ 10 -

If the tail light to be encased is rectangular or square with substantially straight and parallel upper and lower longitudinal edges, the elongated electrically conductive heating strips 16 are spaced approximately 2.54 cm (1 inch) from one another and are parallel to one another and are straight. When the upper and lower edges of the tail light are bent length or from each other of different configuration, the elongate resistance heating strip 16 is preferably of the Pahrzeug-designers that extend between the opposed busbars 18 and 19 in about alternate routes. The curvature of the uppermost strip essentially conforms to the curvature of the upper longitudinal edge of the taillight and the lowermost elongated conductive heating strip runs in accordance with the shape of the lower edge of the taillight.

The ends of adjacent strips 16 are located at their points of contact "with the busbars at a distance of about 2.54 em (1 inch) from the adjacent strip which is connected to the same busbar; the formation of the intermediate strips is graded from strip to strip. This ensures a progressive change in the design from the top to the bottom strip. If the opposite busbars 18 and 19 are subjected to a potential difference of 12 volts with the heater designed in this way, an essentially uniform heat distribution of approximately 0.027 results to 0.03 watts per cm (25 to 30 watts per square foot) by the - - "- ' r * 00980971064

- 11 entire field of vision of the tail light.

To protect the heating element and the busbars from this, that they are excessively exposed to the outside world become the Strip 16 and the "'.. busbars .18 and 19 all" when installing mounted on the inner surface of the taillight . In these circumstances, a protective cover was not used for found necessary.

The strips 16 and "the busbars 18 and 19 become simultaneously applied by the silk screen technique described above. The coated sheet of glass is then bent onto a Shape with a correspondingly shaped rail concave bead attached, but which has a slightly smaller area than the glass pane after bending.

The mold provided with glass is placed in an oven, where the glass is heated to a temperature that is sufficient that the glass plate conforms to the die or «mold surface is bent »During this heating process, the finely distributed one melts metallic ceramic frit on the glass surface, the looks up, and the one concave while bending Gets curvature. When the glass is fully bent, the sheet of glass is removed from the hot atmosphere and as quickly as possible cooled to produce a tempered sheet of glass. Since the

009 809/108 4

- ■■ '- ■' ...:. '■■' ■ ■■ "" ■■ - ¹² - .... ■ "■. '■ - .."' ■. "."'■■ ■ ■ -, ■ · ■

Strip 16 and the bus bars 18 and 19 during the heating process melted on the upper concave glass surface have been, they remain exactly in the form in which they were placed on the cold glass through the stencil during the silk screen process when the glass is quenched.

Preferably, each feed wire one flat copper braid is more sufficient Current carrying capacity equivalent to # 14 solid copper wire so that any loss of power in the bus bars is minimized. This results from the heated ones Busbars rather than dissipating the heat as the strips 16 expand. The free ends of the feeder wires ■ 24- and "26 are loosely connected to the ceramic silver collection rails 18 and 19 placed and with their neighboring Busbar through spaced-apart soldered connections 28 connected> preferably at intervals of about 5.1 cm (2 inch). For example, a flat tin-copper Litzö, sold as Preparation No. 1231, equivalent to No. 14 AWG manufactured by Alpha Wire Corporation of Elizabeth j New Jersey, to the ceramic-silver collecting technology 18 and 19 soldered on, using a tin-lead-silver solder which contains 70 wt .- ^ lead, 27 # tin and 3 ^ silver. This is done by the company Belmont Smelting and Refining Company of Brooklyn, New York as Lot No. 5701. A suitable flux for the solder is placed under the goods are called NOEOHODE. solder paste distributed by the company

009809/1064 '

M.W. Dunton Company of Providence, Rhode Island will. "". '

The multiple connections of the feeder wires to each of the busbars reduce the length of the current path through each part of the busbar to a reasonable distance, which is not an unreasonable distance Loss of electrical energy causes the busbars to heat up. The loose connection of the feed wires on the busbars it allows the former to be seen between the spaced connections 28 extend. At the same time only the parts of the feed wires 24 and 26 that are not are arranged over the bus bars 18 and 19, with the insulation 30 covered. This increases the contact area between the lead wires 24 and 26 and the busbars 18 and 19, - ■ " in order to further reduce the heat loss in the busbars, so that the heating elements 16 have the largest possible Can represent a portion of the total resistance of the heating circuit.

As mentioned above, by using the high impedance, low resistance coils 14 and 15 in the circuit shown in Fig. 1, the antenna circuit is from earth at. Radio frequency isolated. Whenever the radio receiver is in operation, the coils 14 and 15 thus isolate the radio antenna circuit from earth and enable the circuit consisting of the busbars 18 and 19 and the electrically conductive elements 16 - ^;

OO00O9V10 & 4

Circuit 11 by means of its connection to the radio antenna circuit 20 serves as a radio antenna through the antenna wire 17; regardless of whether the circuit 11 with the battery 12 through Closing the battery holder 13 is connected.

The embodiment illustrated in FIGS. 4 to 7 shows a ^ ^e in layers constructed windshield 30, which has a first, .Glasschicht 32, a second glass layer 33 and a thermoplastic intermediate layer 34 of a material such as veichgemachten polyvinyl butyral, located between the Giasschiehten Electrically conductive wires 35 of a material such as nickel-chromium steel, tungsten or the like are embedded on the surface of the plastic interlayer 34 and extend between a pair of electrodes or bus bars 36 and 37 j which are close to opposite longitudinal - Lateral edges of the area to be heated of the intermediate layer F ■ "■" ■■ 34 extend.

The 6-glass layers 32 and 33 ^and the intermediate layer 34 have adapted curvatures and essentially identical floor plans with the exception of a notch part 38 along each longitudinally extending side edge of the glass pane 33. The notch part has a side dimension which is sufficient that it is laterally inside the inner boundary of the busbar 36 or 37 extends.

' 009809/1064:

The wires 35 are, preferably, of small diameter 0.0005 om (0.0002 inches) to 0.005 cm (0.002 inches). they are parallel, essentially equidistant, about 8 to per inch and extend from the busbar 36 to the busbar 37. The busbars are preferably thin strips of conductive metal, such as copper, and across opposite ends of the wires ^ 35 placed. The copper strikes "; are about 0.8 cm (5/16 inch) wide and about 0.013 cm (0 * 005 inch) thick and extend with their outer sides about 0.16 cm (.1- / 16 inch) inside the margin the windshield.

An angle member 41 of moisture impervious material, such as a curved thin disc of aluminum, encloses the notch portion 38 to form a chamber which is filled with resin 42, as described below. The member 41 has a solid wall 44 which is parallel to the major surface of the laminated windshield 30 and an apertured and chime wall 46 which is angled to the solid wall 44 for engagement to step with the edge surfaces of the glass sheets 32 and 33. A pressure sensitive adhesive layer 48 is disposed on the inner surfaces of walls 44 and 46. The angle member 41 is slightly longer than the notch part 38 ^s . The solid wall 44 is slightly taller than the width of the notch portion and the apertured and grooved wall 46 with a width substantially equal to '

009809/106 4

equal to the thickness of the windshield made up of layers 30 is.

Collector rails 36 and 37 are adhered by pressure. A Adhesive has a thin film of polyvinyl butyral, dissolved in chloroform, along the adjacent opposite Sides of the intermediate layer, including the portion of the intermediate layer facing the notch portions 38. Any busbar 36 or 37 has a width which is slightly smaller than that of the notch part so that its outer edge recesses within the outer edge surface of the part of the glass layer 32 which faces the notch part 38 adjacent thereto.

A lead wire 39 similar to lead wire 24 is attached to busbar 36 within notch portion 38 along the top
Edge of the windshield 30 is soldered, while a feed wire 40 similar to the feed wire 26 to the busbar 37
within the notch part 38 along the lower longitudinal edge
the windshield 30 is soldered. The feed wires 39
and 40 are encapsulated with insulating material except at their free inner ends. The uninsulated free ends are soldered to the busbar 36 and 37, respectively. The ends of the
electrically conductive wires 35 are in electrical contact
with the bus bars 36 and 37.The latter therefore serve as a connecting means between the supply wires 39 and 40 and the

009803/1084

Antennas or heating wires 35.

The chamber formed by the notch portion 38 is filled with a filler 42 of electrical insulation material that is resistant to moisture is resistant, filled. This can be a pre-formed link made of insulating material, such as reinforced with fiberglass Be resin, for example with a pressure sensitive j Chen adhesive is coated. Such a preformed limb however, it must conform exactly to the notch portion 38 which contains the feed wire for the busbar connection. The immediate The technique described below was found to be the most suitable for the insulation of the exposed wires and their connecting means from electrical contact with the metal frame during of a serial simulation test found. ■

In connection with in particular FIGS. 6 and 7, a wall 46 provided with openings or grooves with a central ~ - arranged groove 54 provided just sufficient width to allow a margin. create that makes it possible Angle member 41 fits over the feed wire 39 or 40 when the ■ Angle member against the central part of one of the edges of the Windshield is placed around the grooved part 38 to include the grooved glass pane. In the one with openings or Grooved wall 46 are additional openings 56 and 58 ·. intended. An opening is used to introduce quick-setting molding resin as an electrical insulation material,

009809/1064

while the other opening and groove 54 allow the \ Air will escape from the chamber as the resin is introduced.

The article described above is made in the following manner. A pair of glass panes 32 and 33 are placed on top of one another, with a suitable release material between the layers is arranged. The one provided with the grooved parts 38 Disk 33 is placed under disk 32. The two sheets of glass are usually made from sheet glass or river glass commercial sodium-lime-glass mixture. The two Panes are used in the manner described for bending onto a glass bending form with an upward-facing plan form surface laid out by a concave contour in plan view, the loaded with glass The mold is exposed to sufficient heat to cause that the glass panes conform to the upward-facing mold surface the flexible arm will be.

After the discs to d _N have been bent he desired curvature and according to a controlled heat history were cooled, they are removed from the bending mold angeqrdnet and into a sandwich with a layer of plasticized polyvinyl butyral, said antenna wires are embedded therein and the excess wire from the Plastic protrudes. The wires are embedded in the plastic layer using a series of hot needles. A typical technique for sewing one in

. . 009S09 / 10S4

- 19 ■ -. ■. '

thin wire in a layer of insulating material, such as in the plastic interlayer 34, is in the U.S. patent 2,813,960 by EgIe and Bethge. The wires 35 are as shown straight, stretching. But you can can also be sewn in a sinus shape to avoid any bending processes to reduce.

After the glass-plastic sandwich with the curved glass panes on opposite sides of the plastic containing the wires has been erected, the arrangement is subjected to the commercial lamination process. One suitable such process is described in U.S. Patent 2,948,645 (Laurence A. Keimj assigned to PPG Industries, Inc.). As a first step in this lamination process, the periphery and edge of only the assembly is enclosed within a flexible channel-shaped member made of liquid impervious material to form a conduit near the periphery of the interfaces between the intermediate layer and the bent glass layers. To remove the air between the interlayer and the glass sheets it is evacuated from the line _t wherein the pumping is also maintained while the enclosed assembly is heated in a furnace to a temperature between about 66 ° 0 (150 ° F) and 177 ° G (350 ° P). The furnace is essentially under atmospheric pressure. Dae channel-shaped

009809/1064

Link is removed when the edge portion is connected. The assembly is a last! Amination (layering method) at a pressure between about 45 "5 kg per square inch (100 pounds per square inch) and 113.5 kilograms per square inch (250 pounds per square inch) at a temperature between 88 ^o C ~ (19Q ^O F) and 163 ⁰ G (325 ⁰ F) until the entire area of the arrangement is worked up. . *

After the assembly is stacked, extra care is taken to clean it to remove oil from the notch portion of the assembly to be removed in the event that the last stratification step ' has been carried out in an oil autoclave. Excess plastic will be cut and the plastic edge will get closer attached to the glass surfaces by rolling edges. A typical edging process is shown in U.S. Patent 2,999,779 (John W. Morris) and an apparatus for performing this method is shown. The feed wire 39 or 40 is taken care of the protruding surface of the busbar 37 is soldered.,

The angle member 4I is then through the pressure sensitive adhesive 48 glued so that it rests against the windshield 11 and the notch part 38 completely covers. This slides the groove 54 around the feed wire 39 or 40, around the chamber formed by the notch portion 38. Suitable. Adhesives include plasticized polyvinyl butyral and some of the following commercially suitable materials that

■ '■ "■', 0098-09 / 1084. ■" ^ · ''

distributed under the following brand names by the following companies are: Poly EM, sold by G-ulf Oil Corporation of Pittsburgh, Pennsylvania} Eastman 910, distributed by Eastman Kodak Corporation of Rochester, New York; and . Tackmaster 1477 »distributed by PPG Industries, Inc., publ Pittsburgh, Pennsylvania.

The angle member is preferably made of a moisture-impermeable Material formed. Thin aluminum disks have been found to be quite suitable. For an exemplary notch part, which is 5.08 cm (2 inches) long and about 1.02 cm (0.4 inch) wide is a partially tempered flat aluminum disc, which is 8.9 cm (3 1/2 inches) long and 1.9 cm (3/4 inch) wide, perforated to form openings 56 and 58 and Uut 54. She was then along a lengthwise extending to the disk Axle bent around one with grooves or openings To form wall 46 which is 1/4 inch (0.6 cm) wide, and a solid wall 44 1.2 cm (1/2 inch) wide. Other suitable materials are sheet-like Lead, copper washers and the like. '. ·.

After the windshield has passed a visual inspection and the angle member 41 is attached to the windshield 30 to umzuwan- 'the notch portion 38 to a closed chamber. your, the windshield is aligned so that the holes 56 and 58 of the angle member 41 look upwards. The filling 42 '

009809/1064

of electrical insulation material is through one of the openings 56 or 58 of the angle member 41 molded in. use finds a fast curing water resistant resin such as polysulfide resin called Thiokol, sold by the Thiokol Chemical Corporation ,. Bristol, Pennsylvania} or a Silicone vulcanizable at room temperature, such as 615 RTV k Silicone supplied by General Electric Company, Scheneetady, New York, or Scotchcast 225 electrical resin made by the company Minnesota Mining and Manufacturing Company, St. Paul, Minnesota is distributed »All materials with the property within Curing 24 hours are called "fast curing" Materials for the purpose of filling chambers with insulation material, designated.

If excess resin has passed through the other opening 58 and the. centrally arranged groove 54 flows out, is through the Wän-P de 44 and 46 of the angle member 41 with enclosed chamber Resin 42 completely filled. Any excess resin that is in a is introduced with its openings facing upward chamber, forms small mushroom-shaped domes that mechanically fix the angle member at the point. The resin is an exhibition - Sufficient insulation of the free, non-insulated end of the feed wire 39 or 40, as well as the connecting means, . [-. "■ '.. ■ _.- ■■■ - ..

which consist of the busbar and the heating wires. she are isolated from any electrical connection to the

009809/1064

Metal of the automobile body in which the windshield is to be installed. .

A second molding process is preferably used to fill the opposite notch part carried out after the other Feed wire 40 or 39 soldered to busbar 36 or 37, respectively and after the stacked windshields have been attached to a shipping submold. They are transported with the windshields that way are aligned so that the opposite side to be filled with resin

lying notch part 38 looks upwards. The one for the filling

I *

Suitable materials have a short "pot life" of the order of a few hours, depending on the change made by depends on the choice and amount of accelerator used, as described in the literature of the suppliers of these materials is. After 24 hours these materials have set sufficiently that the windshields can be used without risking the system's moisture resistance characteristics loses, can be transported. It is necessary that Store frames or grids long enough to allow the resin to harden before installing the windshields in the molds will. To be on the safe side, each frame containing a number of windshield panels should stand overhead the molding operations are complete for the resin to settle before the frame of the windshield is transported.

009809/106 4

- ^; "^ - ■■■ - _; - 24 - ■ - - -V.- '. -."■' ■■ ,,; 'y is dated.

In an exemplary circuit for an AM and / or FM radio in accordance with the invention, a 12? Olt system for an automobile and a heating area of about 60.9 cm (24 inches) by 122 cm (48 inches) are used, where there is a resistance of about 0.8 ohms from busbar to busbar _e. Coils 1: 4 and 15 are air-core radio frequency chokes and enamel-insulated turns of Ur, 15 copper wire wound in two layers of approximately 150 turns along a length of approximately 15.2 cm (6 inches).

Automobiles with only FM radios have been shown to see the heating circuits 11 behave like antennas for FM radios even in the absence of the coils 14 and 15. The wiring in the The system may provide sufficient inductance to isolate the FM radio antenna circuit from ground necessary for reception of signals from FM stallons are sufficient.

Since many motor vehicles are equipped with AM-FM radios, for the sake of complete disclosure, FIG. 8 shows an alternative embodiment of a circuit which includes a combination of heater and antenna for AM-FM radios in motor vehicles. According to the present invention, FIG. 8 ^; an electrical circuit that connects the radio antenna circuit from earth

00980971084

isolated while the antenna can serve as a heater, though they, as in the first embodiment, exposed to direct current is. The circuit also includes means for switching of wavebands.,

The heating and antenna circuit 11 of the Pig. 8 contains elongated conductive elements 16 parallel to each other and between two busbars 18 and 19, as in Fig »1, are connected. The antenna lead wire 17 connects the elements 16 with one AM-FM radio antenna circuit 120 through busbar 18. Line 17 is disconnected from ground in a slightly different manner than in Fig. -1.

The earthed battery 12 is connected with its positive connection via an AM-FM-Sehaltkreis 61 with the busbar 18, which is also connected to the antenna lead wire 17; the ground terminal of battery 12 is through another AM-FM circuit 62 and ground connections to the automobile body connected to the busbar 19.

The circuit 61 has an oscillating or tuning circuit T5 on, which is constantly fuzzy on the mean value of the AM band is matched and lies in a parallel branch 64. The circle 61 also has another one constantly on the mean of the FM band fuzzy tuned oscillating or tuning circuit 14 in another parallel branch 66. The circuit

0 0 9 8 0 9/1064

contains a constantly fuzzy on the mean of the AM band 'tuned oscillating' 'or tuning circuit T1 in a parallel branch 67 and another on the mean value of the FM band unsharp tuned oscillating or tuning circuit T2 in another parallel branch 68.

Each tuning circuit T1 to T 4 has an inductance and a capacitance of selected size for the desired tuning, the tuning circuits being arranged parallel to one another. For example, the tuning circuits T1 and T3 for AM tuning to 1000 kHz can have a capacitor with a capacitance of 51 ppi ^{1 in} parallel with a coil with an inductance of 50O uH, while the FM tuning circuits T2 and T4> are tuned to 100 MHz have a capacitor with a capacitance of 12.7 YfR in parallel with a coil with an inductance of 0.2 uH. They can also include a wire with the required inductance at the desired frequency. ; . ■ ■ -. ■ ";."",

The switch SW-1 has a contact 77 for connecting the tuning circuit T1 in the branch 67 with the busbar 19 and a contact 78 for connecting the tuning circuit T2 in the branch 68 with the busbar 19. The switch SW-2 has a contact 74-to Connect the tuning circuit Ϊ3 in branch 64 to the busbar 18 and another contact "76 for connecting the output

009809/1064

circuit T4 in branch 66 with busbar 18. The two Switches SW-1 and SW-2 are mechanically coupled in order to simultaneously activate both of the ÄM tuning circuits TT and T3 via contact 77 and 74 to connect to busbars 19 and 18, respectively, in one position when radio 120 is tuned to an AM wavelength is. When switches SW-1 and SW-2 are switched to contacts 78 and 76, respectively, PM tuning circuits replace T2 and T4 im Branch 68 or 66 the AM tuning circuits T1 and T3 in the circuits, which create a connection to the busbars. The tuning circuit arrangement thus isolates the radio ο antenna circuit from earth regardless of whether the radio 120 is tuned to the AM or PM broadcast range.

In this example, each pair of voting circles serves, either the one that contains the AM tuning circles Tl and TJ, or that which contains the PM tuning circuits T2 and T4, the same puncture as the coils 14 and 15 at the embodiment according to Pig. 1. By switching the Switches SW-1 and SW-2 in phase, the radio can receive signals from both the AM broadcasting range and the PM broadcasting range received by electrical circuit 11 which is effectively isolated from earth.

-While the 'tuning circles of the Pig. 8 with Fixed tuning have been described, it is of course a lightweight, adjustable inductor and / or

009 809 / 106A

adjustable capacities to use to vote on to achieve the exact frequency to which the radio is tuned. Under such circumstances, the radio listener sets the tuning circuits Tt and T3 or T 2 and 14 in unison to a maximum To obtain impedance that leads to the maximally strong received signal. In particular, the branches 67 and 64 can be adjustable Tuning devices Τ · 1 and T3 contain the appropriate

■■■■ - ■ '■

are for the AM range, while branches 68 and 66 have adjustable tuners T2 and T4 which are suitable for the FM range. This adjustable tuning enables the antenna to receive a strong signal for the radio receiver at any frequency in its waveband, as long as the tuning device is properly tuned and the switches SW-1 and SW-2 are properly tuned to the appropriate desired range ( AM or FM) are switched . ■ -.'- ■ "■". - ■■■■ .- ■■ ■■ -.-. " - \ - ■ -" ■ "■ -. '". .; . ' ^/: ■■■■ ■■ -7 '. ^y::

The circuit of FIG. 9 corresponds to that of FIG. 1 with the exception of the resistance coils 14 and 15, which have been omitted. In order to isolate the radio antenna from the earth, the other is the welter the radio is connected to a counterpoint earth 31. To this Reaching the end is the opposite pin for the radio isolated from earth 29 for the heating circuit. She stands due to the connection to the ungrounded battery terminal another potential related to earth. If thus the battery switch 13, is closed, allows the

009809/1084

power source into the heating wires 16 through the busbars 18 and 19 conducted current so that the circuit 11 serves both as a radio antenna and as a heating circuit to prevent moisture, such as precipitation or moisture, formed on the window surface Ice, remove. When the battery switch 13 is open, the heating does not work. Then the wires 16 receive but still radio frequency signals and continue to serve as an antenna for the radio.

In most cases, coils 14 and 15 are for AM reception suitable without any inserts. The embodiment 8 is usually sufficient to obtain a signal equivalent to that provided by a typical pole antenna is preserved in her own position. The embodiment developed according to Fig. 8 when appropriately tuned. is and adjustable resistances and / or capacitances in the corresponding voting circles used, a signal which equivalent to that obtained by the partially protruding pole antenna currently in use.

The devices disclosed above use a pair of "solid" Impedance chokes, tuning chokes and tuning circuits for isolating the radio antenna circuit from the voltage source;. for the heating circuit. However, other systems can also be used which allow an electrically conductive element to act as an antenna at radio frequencies as well

0098 0 97 108 4

as an electric resistance heating element of a DC circuit

to serve. For example, this can be powered by the 12 volt battery System must be grounded through a separate bus bar isolated from the metal vehicle body, which is referred to as earth serves for the antenna. Or, * if the automobile body is electric is not conductive, e.g. if it is made of fiberglass, an H wire radio antenna earth can be electrically connected to a separate wire earth be isolated for the battery powered DC system.

The electrically conductive element 16 of FIG. 9 can be connected to the earth connection the battery instead of the ungrounded connection. .

To support the electrically conductive elements in a layered glass unit, a glass sheet surface or an intermediate layer can be used. The electrically conductive ■ Ψ. Elements can be oriented as desired, regardless of whether the window is monolithic or stacked.

98 097 10 64

Claims (12)

Claims 1. ^ Clear window marked with a by an electrical circuit to be heated area having a facing towards the area of electrically conductive element, a source of DC electrical potential and means for connection between the electrically conductive element with the source to a heating circuit to "form _f by means (17) for connecting the electrically conductive element to a radio antenna circuit (20) and means (14 »1 * 5} 31) for isolating the radio antenna circuit from the voltage source (12) so that the electrically conductive element serves as a heater and antenna. 2. Window according to claim 1, characterized by the fact that the isolation means (14, 15) has two means with high impedance for alternating current at radio frequencies and a low DC resistance of the connection between opposite sides of the electrically conductive element (.16), wherein one of the insulation means (15) is grounded and the other (14) is connected to the direct current source (12) and 'that the radio antenna circuit (17, 20) parallel to the earthed Funds is connected. CQ9809 / 1064 3. Window according to claim 1, characterized in that the Medium high impedance can be adjusted depending on the wavelength to which the radio is tuned. 4 «window according to claims 2 or 3, characterized in that that each isolation means has parallel branches (TI, 12} T3, T4) has, which are tuned to the AM or FM frequency range and means (SW-1, SW-2) for simultaneously switching from one to the other of the parallel branches each the isolation means so that one branch of each of the isolation means is tuned to the same frequency range at the same time is like a corresponding branch of the other isolation emitters. 5. Window according to claim 1, characterized in that one the connections of the direct current potential (12) is grounded (29) and that there is a counterpoint (31) for the radio antenna circuit (20) is present. 6. Window according to claim 5, characterized in that the Fahraeugkörper and an isolated from the vehicle body, 'Electrically conductive earth for the earthed connection and provides the opposite point, or correspondingly for the opposite point and earth for the earth connection. 009809/1064 7. Window according to one of the preceding claims, characterized by a pair of spaced busbars adjacent to one spaced apart A pair of opposite side edges of the area extend and are connected to the electrically conductive member, and connected by one to each of the bus bars Feed wire for feeding the potential to the electrically conductive element. 8. Window according to claim 7 »characterized in that the electrically conductive element connecting the busbars a series of essentially parallel lines electrical having conductive material. 9. Window according to claim 8, characterized in that the Busbars and lines made of electrically conductive Material are arranged on the surface of the window. 10. Window according to claim 9 »characterized in that the Window consists of a monolithic pane of glass. 11. Window according to claim 8, characterized in that the window consists of a pair of glass panes layered (laminated) on opposite sides of a transparent, thermoplastic intermediate layer and the lines
electrically conductive material from the intermediate layer • are carried. _{0 0 9 8} fl £) / 1 0 6 * 12. Window according to one of claims 8 to 11, characterized in that the busbars are transverse to the length of the Area along opposite longitudinal edges of the area and the lines extend electrically conductive material substantially along the area extend. · >'■: ■ ■ ■.' ^: ■■ ■ - .. ο Window according to one of Claims 8 to 11, characterized in that that the busbars are essentially longitudinal of the area along the opposite transverse ridges of the Area and that the lines are made electrically conductive material extending across the area. 009809/1064 5 * Γ Blank page