US3579243A

US3579243A - Windshield antenna system

Info

Publication number: US3579243A
Application number: US848799A
Authority: US
Inventors: Richard T Dickason; John A Richardson
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1969-08-11
Filing date: 1969-08-11
Publication date: 1971-05-18
Anticipated expiration: 1988-05-18
Also published as: FR2058191A1; DE2033726A1; FR2058191B1; BR7020344D0; GB1276057A; JPS4842367B1

Abstract

An improved windshield antenna system is described in which a pair of laminated glass sheets forming the windshield contains a pair of antenna wires adhered to the laminating interlayer. The wires have free ends which extend out beyond a cutout portion formed in one of the glass sheets. The free ends of the wires are terminated to an attaching area of a conductive terminal which terminal is received in the cutout portion of the glass sheet. An electrical lead is also connected to the conductive terminal at the attaching area. A nonconductive tab is affixed to one surface of the glass sheet away from the cutout portion of the one glass sheet. The tab holds the electrical lead in a relatively stable position with respect to the attaching area of the conductive terminal at which the lead is terminated to the antenna wires. A potting compound overlies the region of the termination of the antenna wires and the electrical lead to the attaching area of the conductive terminal.

Description

United States Patent [72] Inventors Richard T. Dickason Birmingham; John A. Richardson, Harper Woods, Mich. [21 Appl. No. 848,799 [22] Filed Aug. 11, 1969 [451 Patented May 18, 1971 810,814 3/1959 GreatBritain ABSTRACT: An improved windshield antenna system is described in which a pair of laminated glass sheets forming the windshield contains a pair of antenna wires adhered to the laminating interlayer. The wires have free ends which extend out beyond a cutout portion formed in one of the glass sheets. The free ends of the wires are terminated to an attaching area of a conductive terminal which terminal is received in the eutout portion of the glass sheet. An electrical lead is also connected to the conductive terminal at the attaching area. A nonconductive tab is affixed to one surface of the glass sheet away from the cutout portion of the one glass sheet. The tab holds the electrical lead in a relatively stable position with respect to the attaching area of the conductive terminal at which the lead is terminated to the antenna wires. A potting compound overlies the region of the termination of the antenna wires and the electrical lead to the attaching area of the conductive terminal.

Patentd 'a'y18,1911 T 3,579,243

ATTORNEYS wrNnsiiiistb ANTENNA SYSTEM BAC KGROU ND OF THE INVENTION In the recent past, windshield antenna systems have been introduced for use in conjunction with the radio receivers mounted within automotive vehicles. More particularly, the antenna for the radio is placed in the resinous interlayer which laminates together the sheets of safety glass utilized for forming the windshield of the vehicle. In general, the antenna system is formed by a pair of fine wires which are positioned for a portion of their length in the central portion of the glass. The wires extend from the base of the windshield upwardly to a point near the top of the windshield. The wires then extend outwardly along two diverging legs to termination points near the top side edges of the windshield.

The antenna wires, in order not to impair visibility through the windshield and detract from the appearance of the vehicle, are formed from wire of a very fine diameter. Since the fine diameter wire is used for the antenna system, the manner in which the antenna wire is terminated to an electrical lead which may be connected to the radio is of great importance. The termination is important so that during installation and utilization of the windshield antenna, substantial stress loads are not applied to the termination point of the wires. Since the wires are of such a fine diameter, any substantial stress load applied thereto would cause a rupture of the termination between the wires and the electrical lead and thus an interruption in the use of the antenna system.

The improved'antenna system of this invention is designed to eliminate two problems previously encountered in the termination of the very fine diameter wires used in windshield antenna systems. More particularly, the windshield antenna system of this invention is designed in a first improved aspect to provide termination elements which will not move during the termination procedure to sever or to sheer the fine wires forming the antenna. The windshield antenna system also provides in a second improved aspect a connection between the electrical lead and the fine antenna wires which is so constructed that if external forces are applied to the electrical lead, the forces are transmitted through the termination elements to the glass sheets rather than to the junction formed between the antenna wires and the electrical lead.

SUMMARY OF THE INVENTION This invention relates to an antenna windshield system and, more particularly, to the manner in which an antenna windshield system is terminated so that the antenna might be connected to the radio of an automobile vehicle.

In general, an antenna windshield system is formed from the following elements: a first sheet of glass, a second sheet of glass having a cutout portion overlying the first sheet of glass, an interlayer of resinous material bonding the two sheets of glass together in an assembled condition, and at least a pair of antenna wires adhered to the interlayer between the glass sheets. The antenna wires extend upwardly in the central portion of the windshield and then outwardly along diverging leg portions which extend in opposed directions across the top of the windshield. The antenna wires, at their free ends in the central portion of the windshield, are initially exposed for a portion of their length at the cutout portion of the second glass sheet.

In accordance with the structure of the windshield antenna system of this invention, a conductive terminal is formed to be receivable within the cutout portion of the second glass sheet. An electrical lead is also provided which is insulated over a major portion of its length. The lead has an exposed end. An attaching device is provided on the conductive terminal for securing both the free ends of the antenna wires thereto and the exposed end of the electrical lead thereto. A nonconductive tab is affixed to a surface of the glass sheets. This tab holds an insulated portion of the electrical lead in a relatively stable position with respect to the exposed end of the electrical lead which is attached by the attaching device on the conductive terminal to both the antenna wires and the terminal. A sealant overlies the region of the pair of glass sheets wherein the cutout portion is located in order to seal the conductive terminal, the antenna wires and the exposed end of the electrical lead from the elements.

In greater detail, the conductive terminal is formed so as to have an extending portion which engages at least a small surface area of the cutout portion of the second glass sheet whereby an opening is left between most of the terminal and the surface of the second glass sheet defining the cutout portion thereof. The initially exposed portions of the antenna wires located at the cutout portion of the glass sheet pass through this opening. During the assembly of the antenna system, any movement of the conductive terminal will not cause a sheering of antenna wires between the terminal and the surface of the cutout portion of the second glass sheet because of the presence of the opening in this area.

In still greater detail, the nonconductive tab is affixed to the surface of the first glass sheet away from the cutout portion of the second glass sheet. This tab has a portion thereof defining a passageway extending along the edge of the assembled glass sheets. An insulated portion of the electrical lead is received in close confining relationship within the passageway. Since the passageway confines the insulated electrical lead, any force applied to the unexposed end of the electrical lead is transmitted through engagement of the insulated portion of the lead and the passageway to the plastic tab and then to the glass sheets to which the tab is affixed. In such a manner, the force applied to the lead is not, in turn, applied to the connection formed by the antenna wires, the attaching device and the exposed end of the electrical lead.

Thus, the structure of this invention eliminates two problems heretofore encountered in fabrication of the antenna windshield system. The first problem solved is that the conductive terminal to which the antenna wires are terminated cannot be moved against the antenna wires so as to cause a severing of the same between the terminal and the cutout surface of the second glass sheet. The second problem solved by the antenna system of this invention is that any force applied to the electrical lead connecting the antenna wires to the radio will be transmitted from the lead to the sheets of glass rather than to the termination of the antenna wires and the lead.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view showing the improved portion of the windshield antenna system of this invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1 showing in greater detail the structure of FIG. 1.

FIG. 3 is an exploded, isometric view of the various elements utilized in the formation of the windshield antenna system of this invention.

FIG. 4 is a diagrammatic view of a windshield having an antenna system located therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention relates to a windshield antenna system and, more particularly, to an improved termination for the fine antenna wires utilized in such a system. The windshield antenna system is shown in FIG. I and is generally designated therein by the numeral 10.

The following basic parts are utilized in the formation of the windshield antenna system 10. A first glass sheet 12 and a second glass sheet 14 are laminated together by utilization of a resinous material such as a polyvinyl butryl interlayer 16 in a normal laminating operation. The glass sheets are normally 0.l25 inch in thickness and the interlayer is normally 0.030 inch in thickness. The second glass sheet 114 has a cut out portion 18 formed therein for the purpose of exposing the ends of a pair of fine antenna wires 20-20. These fine antenna wires, for example, may have a diameter of approximately 0.0054- 0.0056 inch and be formed of copper having a resistance of approximately 415 ohms per 1,000 feet.

As may be best seen in FIG. 4, the antenna wires extend upwardly from the cutout portion 18 of the second glass sheet 14 to a point at which the ends thereof, laminated between the

glass sheets

12 and 14, extend parallel to the base of the glass sheets. The length dimension of the antenna wires in the direction parallel to the base of the glass sheets is one of the principal controlling factors in the reception characteristics of the antenna. As indicated in FIG. 4, the outwardly turned ends of the antenna wires 20-20 are generally laid in the portion of the windshield wherein the gradient band 22 (indicated by dashed lines at its lower end) is positioned. The gradient band is dark in color and it reduces the amount of light energy which may pass through the upper portion of the windshield. Also, because the gradient band is the darkest portion of the windshield, the extending legs of the antenna are not easily seen from either side of the windshield.

The antenna wires 20-20 are preferably adhered to the resinous interlayer 16 in an initial process operation. Such adherance may be accomplished by laying the antenna wircs out in a prescribed pattern on the interlayer and thereafter ironing the wires to heat them sufficiently so that they become bonded to the interlayer. Thereafter, the interlayer containing the wires is placed between the first glass sheet 12 and the second glass sheet 14 and heat and pressure are applied thereto so that the two glass sheets are laminated into a windshield. Prior to the lamination operation, the free ends of the antenna wires which extend out beyond the cutout portion 18 of the second glass sheet 14 are bent up and laid over the second glass sheet so that they do.not become firmly adhered to the resinous material during the autoclaving step of the laminating operation.

In accordance with the teachings of the invention, a conductive terminal 24 (best seen in FIG. 3) is utilized in terminating the antenna wires 20 so that the antenna wires may be connected to the radio of the automobile vehicle. In greater detail, the preferred conductive terminal 24 is formed from a brass plate, the plate thereafter having a coat of tin placed thereover. The terminal has a thickness of 0.015 inch and may be bonded to the interlayer 16 during the autoclaving step of the laminating operation. In such a case, the conductive terminal is held in proper position during the autoclaving operation by means of a clip so that a secure bond is formed between the interlayer and the terminal.

In accordance with a feature of this invention, the conductive terminal 24 has a pair of extending legs 26-26 (best seen in FIG. 3). The extending legs engage opposite sides of the cutout portion 18 of the second glass sheet 14 whereby a space or opening 28 (FIG. 1) is created between the terminal 24 and the facing surface of the cutout portion of the sheet. In such a manner, if the conductive terminal is moved or otherwise jarred during the assembly thereof, the sharp end or edge of the terminal will not come into contact with and thus sheer the fine antenna wires 20 against the surface of the cutout portion of the second glass sheet. As may best be appreciated from FIG. 1, in an assembled condition after autoclaving, the antenna wires would be underneath the second glass sheet 14 but the free ends thereof would emerge therefrom and pass through the opening 28 between the glass sheet and the conductive terminal. In an alternate form, the conductive terminal 24 may be formed with only a single extending leg which would be located in the central portion of the terminal. This single leg would engage the cutout portion of the second glass sheet between the two antenna wires leaving an opening on either side thereof.

The conductive terminal also has a small projecting portion 30 formed thereon (best seen in FIG. 3). The projecting portion 30 is located intermediate the extending legs 26 of the terminal. The projecting portion 30 extends initially, before the termination of the antenna wires to the terminal, in a direction towards and beyond the exposed edges of the

glass sheets

12 and 14.

An electrical lead 32 is provided which is insulated over a major portion of its length. The electrical lead has an exposed end 34 which is pretinned and a connector end 36 which is utilized for connecting the lead 32 to the antenna input for the radio circuitry.

A nonconductive tab 38 is also provided and this tab may be formed from a material such as acrylonitrilebutadiene styrene copolymer, commonly known as ABS type plastic. The nonconductive tab has a double coated pressure sensitive material 40, such as neoprene foam, placed on a portion thereof extending over a substantial area. The nonconductive tab also has a front portion 42 which has a passageway 44 formed therethrough. Adjacent and forming a continuation of the front portion 42 of the tab is another flat portion 46 which extends along the length of the tab a distance approximately equal to the length of the front portion. The front portion and the flat portion of the tab together define a rear surface 48 (seen in FIG. 2).

ASSEMBLY As previously mentioned, the first and

second glass sheets

12 and 14 are bonded together in a standard laminating operation utilizing the resinous interlayer l6 therebetween. As also previously mentioned, the fine antenna wires 20 may be adhered to the interlayer 16 prior to the laminating operation. In such a case, free ends of the antenna wires 20 are bent out and over the second glass sheet at the cutout portion 18 thereof. As also previously mentioned, the conductive terminal 24 may be secured to the resinous interlayer 16 during the autoclaving operation in the glass laminating procedure.

After autoclaving, the windshield is washed. Thereafter, the free ends of the fine antenna wires 20 are individually brought down and wrapped at least one turn around the projecting portion 30 of the terminal 24. This is best illustrated in FIG. 1 where the convergence of the two antenna wires to the projecting portion 30 is shown. If the antenna wire has some type of a polymetric or paint coating thereover, it is necessary to sand the wires to expose the copper under the coating prior to wrapping the wire around the projecting portion of the terminal.

When the antenna wires have been wrapped about the projecting portion 30 of the terminal 24, the exposed end 34 of the electrical lead 32 is placed in a position on the conductive terminal 24 directly adjacent the projecting portion 30 of the terminal. The projecting portion of the terminal is then folded up and over and clamped down upon the exposed end 34, as is best appreciated by viewing FIGS. 1 and 2. Solder is then flowed over the connection so that an intimate electrical junction is formed between the antenna wires 20, the projecting portion of the conductive terminal 24 and the exposed end 34 of the lead 32.

The electrical lead 32 is preassembled to the nonconductive tab 38 prior to the termination of the exposed end 34 of the lead to the conductive terminal 24 and the antenna wires 20. Once the termination operation has been completed, the operator adheres the nonconductive tab 38 by means of the pressure sensitive material 40 to the surface of the first glass sheet 12 on the side opposite the cutout portion 18 of the second glass sheet 14 (best seen in FIGS. 1 and 2). When this is done, the rear surface 48 of the front portion 42 and the flat portion 46 of the tab 38 engage the edge of the glass sheet 12. The tab thus fonns a barrier for blocking any direct physical contact with the junction.

As will best be understood by reference to FIG. 1, a portion of the electrical lead 32 is doubled back upon itself in that the lead is secured to the terminal 24 and thereafter passes through the passageway 44 of the front portion 42 of the tab 38. By forming the lead back upon itself and passing it through the closely encircling passageway, any force applied as a pulling force to the connector end 36 of the lead 32 will be transmitted by means of the lead 32 to the walls of the passageway 44 and from there to the tab 38 and the glass sheet 12 to which it is adhered. The pulling force, therefore, is dissipated and is not applied to the junction formed by the antenna wires 20, the exposed end 34 of the lead 32 and the projecting portion 30 of the terminal 24. This construction thus accomplishes a second feature of the improved antenna windshield system of this invention.

A sealing compound 50, shown only in FIG. 2, is applied over the termination point of the antenna wires and the exposed end of the electrical lead in order to protect the junction formed therebetween. The sealing material or compound is flowed by any suitable means into the space formed between the cutout portion 18 0f the second glass sheet I4 and the front portion and flat portion, respectively 42 and 46, of the tab 38. For example, a potting compound may be dispensed through a pressurized nozzle arrangement to fill the space as aforedescribed. A suitable potting compound may be formed from a material such as silicone rubber base adhesive. This type of sealing material dries fairly rapidly and once it is dried, it forms a barrier which is impervious to moisture and other types of detrimental materials which could ruin the electrical characteristics of the antenna wire junction.

Thus, there has been described a preferred embodiment of a windshield antenna system in which the antenna wires cannot be accidentally sheared by the terminal to which the wires are to be terminated. Also, the improved windshield antenna system presents a system wherein any pulling force applied to the electrical connector which connects the antenna to the radio of the automobile vehicle is dissipated as a force applied to the glass rather than to the antenna wire junction,

We claim:

1. In a windshield antenna system which includes a first sheet of glass, :1 second sheet of glass having a cutout portion overlying the first sheet of glass, an interlayer of resinous material between the two glass sheets bonding the same together in an assembled condition, and at least a pair of antenna wires adhered to the inner layer between the glass sheets, the antenna wires being initially exposed for a portion of their length at the cutout portion of the second glass sheet, the improvement comprising:

a conductive terminal formed so as to engage at least a small portion of the cutout portion of the second glass sheet to leave an opening between most of said terminal and the surface of the second glass sheet defining the cutout portion thereof, the initially exposed portions of the antenna wires passing through said opening;

an electrical lead insulated over a major portion of its length and having an exposed end;

attaching means on said conductive terminal for securing both said antenna wires thereto and said exposed end of said electrical lead thereto, said attaching means including (1) a small projecting portion formed on said terminal about which the exposed ends of the antenna wires may be wrapped to terminate the same and which may be folded over on the exposed end of said insulated lead to clamp said lead between said projecting portion and said terminal, and (2) electrically conductive solder flowed over the area of said projecting portion on said terminal both to which the antenna wires are terminated and which clamps the exposed end of said insulated lead; a nonconductive tab affixed to the surface of the first glass sheet away from the second glass sheet, said tab having a portion thereof defining an elongated passageway extending along the edge of the assembled glass sheets, said insulated portion of said electrical lead being received in said passageway whereby any force applied to the exposed end of said electrical lead is transmitted through engagement of the insulated portion of sad lead and said passageway to said plastic tab and then to the glass sheets and not to the connection formed by the antenna wires, said attaching means and said exposed end of said electrical lead; and

- sealing means overlying the region of the pair of glass sheets wherein the cutout portion is located for sealing said conductive terminal, the antenna wires and said exposed end of said electrical lead to protect the same.

2. The windshield antenna system as defined in claim I, wherein said projecting portion formed on said terminal extends initially before termination of the antenna wires and clamping of said lead in a direction towards and beyond the exposed edges of the glass sheets.

3. The windshield antenna system as defined in claim 2, wherein said conductive terminal is formed generally in a crescent configuration to conform to the cutout shape of the second piece of glass, opposite ends of the terminal having extending legs which engage the cutout surface of the second glass sheet at the spaced points whereby said opening is left between said terminal and the cutout portion of the second glass sheet for passage of said antenna wires therethrough, and wherein said projecting portion of said terminal is positioned at a location intermediate said extending legs.

4. The windshield antenna system as defined in claim 2, wherein said conductive terminal is formed generally in a crescent configuration to conform to the cutout shape of the second piece of glass, the central portion of said terminal having an extending leg which engages the cutout surface of the second glass sheet at a location between the two antenna wires whereby an opening is left on either side of said extending leg between said terminal and the cutout portion of the second glass sheet for passage of said antenna wires therethrough, and wherein said projecting portion of said terminal is positioned in alignment with the axis of said extending leg,

5. The windshield antenna system as defined in claim 4, wherein said tab is affixed to the surface of the first glass sheet away from the second glass sheet by a binding material initially carried by said tab.

6. The windshield antenna system as defined in claim 5, wherein said portion of said tab defining said passageway also defines a wall which extends along another portion of the edges of the two glass sheets, said wall and said portion of said tab defining said passageway providing protection for said connection of the antenna wires from direct physical contact being made therewith when the edges of the glass sheets are engaged by an object.

7. The windshield antenna system as defined in claim 6, wherein said tab is formed from ABS plastic.

8. The windshield antenna system as defined in claim 7, wherein said sealing means is a potting compound formed from a silicone rubber base adhesive.

Claims

1. In a windshield antenna system which includes a first sheet of glass, a second sheet of glass having a cutout portion overlying the first sheet of glass, an interlayer of resinous material between the two glass sheets bonding the same together in an assembled condition, and at least a paIr of antenna wires adhered to the inner layer between the glass sheets, the antenna wires being initially exposed for a portion of their length at the cutout portion of the second glass sheet, the improvement comprising: a conductive terminal formed so as to engage at least a small portion of the cutout portion of the second glass sheet to leave an opening between most of said terminal and the surface of the second glass sheet defining the cutout portion thereof, the initially exposed portions of the antenna wires passing through said opening; an electrical lead insulated over a major portion of its length and having an exposed end; attaching means on said conductive terminal for securing both said antenna wires thereto and said exposed end of said electrical lead thereto, said attaching means including (1) a small projecting portion formed on said terminal about which the exposed ends of the antenna wires may be wrapped to terminate the same and which may be folded over on the exposed end of said insulated lead to clamp said lead between said projecting portion and said terminal, and (2) electrically conductive solder flowed over the area of said projecting portion on said terminal both to which the antenna wires are terminated and which clamps the exposed end of said insulated lead; a nonconductive tab affixed to the surface of the first glass sheet away from the second glass sheet, said tab having a portion thereof defining an elongated passageway extending along the edge of the assembled glass sheets, said insulated portion of said electrical lead being received in said passageway whereby any force applied to the exposed end of said electrical lead is transmitted through engagement of the insulated portion of sad lead and said passageway to said plastic tab and then to the glass sheets and not to the connection formed by the antenna wires, said attaching means and said exposed end of said electrical lead; and sealing means overlying the region of the pair of glass sheets wherein the cutout portion is located for sealing said conductive terminal, the antenna wires and said exposed end of said electrical lead to protect the same.

2. The windshield antenna system as defined in claim 1, wherein said projecting portion formed on said terminal extends initially before termination of the antenna wires and clamping of said lead in a direction towards and beyond the exposed edges of the glass sheets.

4. The windshield antenna system as defined in claim 2, wherein said conductive terminal is formed generally in a crescent configuration to conform to the cutout shape of the second piece of glass, the central portion of said terminal having an extending leg which engages the cutout surface of the second glass sheet at a location between the two antenna wires whereby an opening is left on either side of said extending leg between said terminal and the cutout portion of the second glass sheet for passage of said antenna wires therethrough, and wherein said projecting portion of said terminal is positioned in alignment with the axis of said extending leg.