Method Of Making An Improved Windshield Antenna System

Abstract

A windshield antenna system includes a first sheet of glass, a second sheet of glass and an interlayer of resinuous material bonding the two glass sheets together. A pair of antenna wires are adhered to the interlayer for most of their length. However, the antenna wires do have free ends projecting outwardly from between the bonded glass sheets at a cutout portion of the second glass sheet. A terminal having a first end portion defining a projecting neck, a main body portion and a second end portion defining a connector tip is formed from a conductive material. At least the body portion of the terminal is bonded to the exposed surface of the second glass sheet with the portion of the terminal defining the projecting neck extending to a position which is located over the cutout portion of the second glass sheet. The free ends of the antenna wires are wrapped around the projecting neck of the terminal. The wrapped wires and the projecting neck of the terminal are deformed into the space provided by the cutout portion of the second glass sheet. An electrical junction of high quality is formed between the wrapped antenna wires and the terminal by applying solder thereto. Any extraneous antenna wire is cut off. The space into which the projecting neck of the terminal and the wrapped antenna wires are deformed is sealed by a sealing material. The main body portion of the terminal is also sealed by a sealing material.

Description

BACKGROUND 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 a radio is placed in a resinous interlayer which laminates together the sheets of 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 a 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, in turn, to the radio receiver is of great importance. The termination is important so that during the installation and utilization of the windshield antenna, substantial stress loads are not applied to the termination point of the antenna wires. Since these wires are of a fine diameter, any substantial load applied to their junction point would cause a rupture of the termination and thus, an interruption in the use of the antenna system.

The method disclosed in this application has been designed for use in terminating fine antenna wires thereby to form a windshield antenna system. The method has been designed to eliminate some of the problems of the prior art in rapidly and efficiently forming a termination structure of high quality. More particularly, the termination structure formed in accordance with the method of this invention is one wherein substantial stress loads are not applied to the termination of the fine antenna wires to a conductive terminal, but rather are applied by the conductive terminal to the glass sheet upon which the terminal is mounted.

SUMMARY OF THE INVENTION

This invention relates to a method of making an antenna windshield system, and more particularly, to the method by which an antenna windshield is terminated so that the antenna is connectable to the radio receiver of an automotive 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 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 from the lower edge thereof and then outwardly along diverging leg portions which extend in opposite directions across the top of the windshield. The antenna wires, at their free or lower ends, extend outwardly from between the two glass sheets at the cutout portion of the second glass sheet.

In accordance with the method of this invention for forming the windshield antenna system, a conductive terminal is formed so as to have a body portion, a first end portion defining a projecting neck and a second end portion defining a connector tip. Once the terminal is formed, at least the body portion of the terminal is bonded to the exposed surface of the second glass sheet in such a manner that the first end portion of the terminal defining the projecting neck extends to a position which is located over the cutout portion of the second glass sheet. The free ends of the antenna wires are wrapped about the first end portion of the terminal. The wrapped wires and the projecting neck of the terminal are deformed into the space provided by the cutout portion of the second glass sheet. An electrical junction of high quality is formed between the wrapped antenna wires and the terminals by soldering the junction therebetween. Any extraneous antenna wire remaining is cut off and discarded.

In greater detail, the space into which the projecting neck of the terminal and the wrapped antenna wires are located after being deformed is sealed by a sealing material. Similarly, the main body portion of the terminal may be sealed by a sealing material if desired. Also, the second end of the terminal defining the connector tip is bent away from the plane of the main body portion of the terminal in a direction away from the exposed surface of the second glass sheet to facilitate the terminal's connection by proper electrical leads to the radio receiver of the automotive vehicle.

In still greater detail, the bonding of the terminal to the glass sheet having the cutout portion is accomplished in the following manner. A piece of the material utilized to form the resinous interlayer between the two glass sheets is fitted between the glass sheet having the cutout portion and the main body portion of the terminal. The terminal is clamped to the glass sheets and, thereafter, the glass sheets and the terminal are subjected to an autoclaving operation wherein the heat and pressure are applied to bond the terminal to the glass sheets. This autoclaving step may be carried out simultaneously with the autoclaving step utilized to laminate the first and second glass sheets together.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing a portion of the windshield antenna system manufactured by the improved method of this invention. FIG. 2 is a cross-sectional view showing greater details of the structure of FIG. 1. FIG. 3 is another cross-sectional view showing the antenna system manufactured by the improved method of this invention installed in an automotive vehicle. FIG. 4 is an isometric view of a conductive terminal which may be utilized in constructing the windshield antenna system. FIG. 5 is a schematic view of a windshield having an antenna system located therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention relates to a method of manufacturing a windshield antenna system and, more particularly, to a method of manufacturing a windshield antenna system which has an improved termination structure for the fine wires utilized as the antenna in such a system. The windshield antenna system is shown in FIGS. 1 and 5 and is generally designated by the numeral 10.

The following basic parts are first assembled by the proper methodology in order to form the windshield antenna system 10. A first sheet of glass 12 and a second sheet of glass 14 are laminated together by utilization of a resinous material such as a polyvinyl butyral interlayer 16 in a normal laminating operation (best seen in FIGS. 2 and 3). The normal laminating operation consists of positioning the interlayer between the two glass sheets, thereafter applying pressure to the two glass sheets to temporarily bind them to the vinyl interlayer, and finally, autoclaving the two glass sheets with the interposed vinyl interlayer. In the autoclaving step, the windshields are immersed in a hot oil bath and the bath is heated and pressure applied thereto. During this autoclaving step, the vinyl interlayer cures and bonds the two glass sheets together in order to form a windshield assembly.

The second glass sheet has a cutout portion 18 formed therein at the central portion of its lower edge 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. The cutout portion 18 may, if desired, be a drill hole through the glass.

As may be best seen in FIG. 5, the antenna wires 20 extend upwardly from the cutout portion 18 of the second glass sheet 14 to a point at which the ends of the wires, 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. 5, the outwardly turned ends of the antenna wires 20--20 are generally laid in a 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 passes 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 processing operation. Such adherance may be accomplished by laying the antenna wires 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 the windshield. Prior to such laminating 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 the free ends thereof do not become adhered to the resinous material during the autoclaving step of the laminating operation.

In accordance with the teachings of the method of this invention, a conductive terminal 24, best seen in FIG. 4, is utilized in terminating the antenna wires 20 so that the antenna wires may be connected to the radio receiver of the automotive 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.

In accordance with the method of this invention, the conducive terminal 24 is formed so as to have a first end portion 26 in the shape of a projecting neck and a second end portion 28 in the shape of a connector tip. Between the first end portion and the second end portion, there is formed a main body portion 30 of the conductive terminal.

As best seen in FIG. 2, the conductive terminal 24 is bonded to the exposed surface of the second glass sheet 14 by utilization of a bonding material 32 between the main body portion 30 of the terminal and the surface of the glass sheet. The terminal is bonded to the glass in such a manner that the main body portion thereof extends away from the cutout portion 18 of the second glass sheet in a direction paralleling the direction in which the antenna wires 20--20 extend away from the same cutout portion. By bonding the conductive terminal to the glass sheet, any forces applied to the conductive terminal are transferred to the glass sheet rather than to the junction which is formed between the terminal's end portion or projecting neck 26 and the free ends of the fine antenna wires. The bonding material utilized to bind the terminal to the glass may be any material such as an adhesive or other suitable bonding agent.

In a preferred way of bonding the terminal 24 to the exposed surface of the second glass sheet 14, polyvinyl butyral material is utilized as the bonding agent. This material is the same material which is preferred for utilization as the laminating interlayer between the glass sheets. A small strip of polyvinyl butyral is placed between the body portion 30 of the terminal 24 and the exposed surface of the second glass sheet. Thereafter a clip or other suitable clamping device is placed over the terminal and the glass sheets so that the terminal is held against the bonding material and the glass sheets. The terminal and bonding material may then be subjected to heat and pressure in an autoclaving operation in order to form the final bond between the terminal and the glass. In a preferred method, the autoclaving step to bond the terminal to the glass sheets may be carried out at the same time as the glass sheets are autoclaved in order to cure the interlayer disposed therebetween and cause the lamination of the two glass sheets.

Once the conductive terminal 24 has been bonded to the exposed surface of the second glass sheet 14, the free ends of the antenna wires 20--20 projecting outwardly into the cutout portion 18 of the second glass sheet, can be terminated to the first end portion 26 of the terminal. The termination is accomplished by taking an individual free end of one of the antenna wires 20 and wrapping it at least one turn about the projecting neck of the first end portion of the terminal. If the antenna wire has a coating of paint or other material thereon for the purpose of protecting the same, it is necessary to remove the paint or other material to obtain a proper termination of the antenna wires to the conductive terminal. The removal of such material may be accomplished by applying fine sandpaper to the free ends of the wires.

Once both of the antenna wires 20--20 have been connected to the first end portion 26 of the terminal 24, the terminal's first end portion is deformed into the space left vacant by the cutout portion 18 of the second glass sheet 14. A small amount of solder 33 (FIG. 2) is applied to the antenna wires and the projecting neck for the purpose of insuring a proper quality electrical junction being formed therebetween. Any excess antenna wire remaining after a portion of the antenna wire has been soldered may be clipped off.

Upon completion of the soldering operation, a sealing compound 34, such as shown in FIGS. 2 and 3, is flowed into the space left vacant by the cutout portion 18 of the glass sheet 14. The sealing material or compound is flowed by any suitable means, for example, through a pressurized nozzle arrangement to fill the space as aforedescribed. A suitable 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, the material forms a barrier which is impervious to moisture and other types of detrimental material which could ruin the electrical characteristics of the antenna wire junction.

As best understood by reference to FIGS. 3 and 4, the second end portion or connector tip 28 of the conductive terminal 24 is bent away from the plane of the body portion 30 of the terminal in a direction away from the exposed surface of the second glass sheet 14. This portion of the conductive terminal is formed so as to be matable with a female electrical connector 36 of standard construction, as best seen in FIG. 3. The female electrical connector is both supported by various body panels 38-40 of an automotive vehicle and connected to the radio (not shown) carried within the vehicle.

As may best be understood by reference to FIG. 2, the main body portion 30 of the conductive terminal 24 can be protected, if desired, by placing a sealing and protecting material 42 thereover. The material 42 is shown only in FIG. 2 and may be a material such as an electrical insulating tape. This insulating tape is optional, but its use is preferred so as to protect the electrical terminal over the greatest extent of its body portion from being attacked by elements which would either ruin or destroy the same.

Thus, there has been described herein a preferred method for manufacturing a windshield antenna system in which any pulling force applied to the electrical connector which connects the antenna wires of the system to the radio receiver of the vehicle is dissipated as a force applied to the glass by the terminal. By applying the force in such a manner rather than directly to the junction formed between the terminal and the fine wires, the junction is protected from damage.

Claims

We claim:

1. A method of terminating free end portions of antenna wires which are adhered for most of their length to a resinous interlayer material bonding two glass sheets together to form a windshield, the free end portions of the wires being exposed in a cutout portion of one of the glass sheets, which method comprises the steps of:

bonding said antenna wires to said resinous interlayer material; forming a pair of glass sheets, one of said glass sheets having a cutout portion at a central location along a lower edge thereof; uniting said resinous interlayer material to said glass sheets with free end portions of said antenna wires extending into and being exposed in said cutout portion of said one glass sheet;

forming a conductive metal terminal having a first end portion defining a projecting neck, a main body portion and a second end portion defining a connector tip;

bonding at least a portion of said body portion of said terminal to the outer, exposed surface of said one glass sheet with said first end portion of said terminal defining said projecting neck extending to a position which is located over said cutout portion of said one glass sheet;

wrapping at least a portion of each of said free ends of the antenna wires around said first end portion defining said projecting neck of said terminal;

deforming said wrapped wires and said projecting neck of said terminal into the space provided by said cutout portion of said one glass sheet;

forming an electrical junction between the wrapped antenna wires and said terminal, and

cutting off any extraneous antenna wire not wrapped around said projecting neck.

2. The method of terminating the antenna wires of a windshield antenna as defined in claim 1 further comprising the step of: sealing the space into which said projecting neck of said terminal and the wrapped antenna wires are located after being deformed.

3. The method of terminating a windshield antenna as defined in claim 2 further comprising the step of: sealing and insulating the main body portion of said terminal which is bonded to the exposed surface of the one glass sheet.

4. The method of terminating a windshield antenna as defined in claim 3 further comprising the step of: deforming said second end of said terminal defining a connector tip away from the plane of said main body portion of said terminal in a direction away from the exposed surface of the second glass sheet.

5. The method of terminating a windshield antenna as defined in claim 1 wherein said bonding step is carried out by: positioning a piece of polyvinyl butyral between the body portion of said terminal and said second glass sheet, clamping said terminal to said glass sheet, and autoclaving said clamped terminal and the second glass sheet whereby heat and pressure are applied to said terminal and the glass sheet.