WO2001099472A1

WO2001099472A1 - Electrical connector unit

Info

Publication number: WO2001099472A1
Application number: PCT/EP2001/006852
Authority: WO
Inventors: Danny Martin; Jürgen Burg
Original assignee: Guardian Automotive-Europe S.A.
Priority date: 2000-06-19
Filing date: 2001-06-18
Publication date: 2001-12-27
Also published as: DE10030066A1; DE10030066B4

Abstract

The present invention relates to an electrical connector unit (10) for the electrical connection of conducting elements (11, 12) on the inner side of a window pane (1) of a motor vehicle, in particular the windscreen, comprising at least one contact area (13) on the inner surface of the window pane (1) and at least one connector (20) attached to the contact area and electrically isolated by an isolation (21), wherein the combined thickness of the connector (20) and the isolation (21) is less than a fraction of a millimeter.

Description

Electrical connector unit

1. Technical Field

The present invention relates to an electrical connector unit for the electrical connection of conducting elements of a window pane, in particular the windscreen of a motor vehicle.

2. The Prior Art

In many fields of technology electric or electronic devices are integrated into or attached to a window pane. A typical example is a sensor of an alarm system detecting the breaking of the window of a building. A further example are the heating lines of a windscreen of a motor vehicle, which are used to defrost or defog the window. These conducting lines are usually printed onto the window and serve to provide due to their electric resistance heat to the window pane. Finally, in order to improve the quality of radio communications antennas are often integrated into the windscreen or the backlites of cars.

In all of the above cases (and other applications) it is necessary to electrically connect the respective device (i.e. the sensor, the heating lines, the antenna etc.) to the external circuitry eif er.tQ supply power or to transmit and receive electric signals. To this end typically electrical connector elements are provided which are on one end attached to the window pane and on the other end to a plug or any other suitable connecting means of the circuitry of the overall system.

Such an electrical connector element, as it is for example disclosed in the EP 0 477 069, comprises usually a flexible cable or a braid with a plug which is soldered either directly or via a connecting metal piece to a metallized part of the surface of a window pane. If such a connector element is used for the windscreen of a car, it is usually arranged on the inner side of the window pane, so that an additional hole in the surrounding frame of the body of the car is necessary to provide an electrical connection to the power supply (for example the battery which is typically arranged under the hood of the car). This additional duct increases the work and thus the costs not only for the preparation of the car body prior to the assembly but also for mounting the window pane to the car body.

Further, the electrical connector element according to the EP 0 477 069 is comparatively big thus making it difficult to hide it either for design reasons or to avoid damages.

Another major disadvantage is that the cable or braid of the connector element tends to vibrate relative to the window pane when the car is operated. This vibration may after some time cause a breaking of the solder connec- tion to the metallized part of the window pane and thus a failure of the overall heating system of the windscreen.

A further electrical connector element is known from the DE 39 37 346, wherein a thin metal foil is during production of a laminated windscreen po- sitioned between the two glass sheets to electrically contact the inner surface of the exterior glass sheet. Although this arrangement leads to an improved stability of the connector element, it can only be used with laminated windscreens and not with window panes made Of a single glass sheet, as for example a typical backlite of a car. Further, the connector element according to DE 39 37 346 can not be mounted after the manufacture of the laminated windscreen is finished. Consequently, there is no flexibility for the car manufacturer to change, if necessary, the position of the electrical connector element on the windscreen. Instead, the complete windscreen must be redesigned.

It is therefore the problem of the present invention to provide a reliable electrical connector unit, which allows an easy, flexible and cost-efficient electrical connection of conducting elements of all kinds of window panes to overcome the disadvantages of the prior art.

3. Summary of the invention The present invention relates to an electrical connector unit for the electrical connection of conducting elements on the inner side of a window pane of a motor vehicle, in particular the windscreen, comprising at least one contact area on the inner surface of the window pane and at least one connector attached to the contact area and electrically isolated by an isolation, wherein the combined thickness of the connector and the isolation is less than a fraction of a millimeter.

Due to the reduced thickness of the connector and the isolation, the negative influence of vibrations of the connector on the attachment to the contact area is greatly reduced.

Further, the electrical connector unit according to the invention facilitates the hiding of the unit, since its elevation over the plane of the window pane is due to its reduced thickness negligible compared to the connector ele- ments of the prior art.

The substantially reduced thickness allows further to arrange the isolation and the connector in a preferred embodimdnt of the invention below a glue bead and/or a seal arranged on the window pane. Such an arrangement pro- vides a more stable attachment of the overall connector unit to the window pane and excludes any mechanical stress on the connection between the connector and the contact area, since the glue bead and/or seal arranged on the window pane creates a second point of attachment.

Finally, the connector can, if necessary, due to its reduced thickness without any additional hole or the like in the surrounding frame be guided from the side directed to the interior of the vehicle to the other side of the window pane, reducing thus the cost for the manufacture of the system (for example a motor vehicle) into which the window pane is integrated.

Preferably, the connector is soldered to the contact area on the window pane and comprises preferably a thin flexible metal band. The isolator is preferably a thin polyimide foil. This material has excellent heat resisting and electrically isolating properties. In a particularly advantageous embodiment two contact areas are provided on the window pane and two metal bands which are integrated into a common polyimide foil. Thus, the overall mechanical stability is even more increased assuring a long lifetime of the connector unit according to the invention.

Preferably, the section of the polyimide foil extending between the glue bead and/or the seal and the contact area is attached, for example by means of an adhesive, to the window pane. As a result, the isolated connector(s) extend parallel to the surface of the window pane, so that a risk of tearing the connector, when the window pane is mounted (for example to the body of a car) is minimized.

Further improvements of the electrical connector unit according to the invention are the subject matter of further dependent claims.

4. Brief Description of the Drawing-

In the following a detailed description of a presently preferred embodiment of the present invention is given with reference to the drawing, in which shows:

Fig. 1 : a top view of a window pane with an electrical connector unit according to a preferred embodiment of the invention; and

Fig. 2: a side view of the preferred embodiment of Fig. 1. 5. Detailed description of a Preferred Embodiment

In the following a detailed description of a preferred embodiment of the invention is presented which relates to an electrical connector unit for the connection of a heating grid of the windscreen or the backlite of a motor ve- hide. It is, however, to be understood that the present invention can also be used in other fields of technology, for example when an antenna or any other electronic device which is integrated or attached to a window pane is to be connected to the respective circuitry.

With reference to Fig. 1, a top view of a part of a windscreen 1 is shown, where a preferred embodiment of an electrical connector unit according to the invention, generally referenced with 10, is attached on the interior side of the windscreen, i.e. the side directed to the passenger compartment. The windscreen 1 comprises a plurality of heat conductors, which are exemplary shown in two groups 11 and 12. In order to supply power to the heat conductors 11, 12 two contact areas 13 are provided. The heat conductors 11, 12 and the contact areas 13 are preferably silk screened onto the inner side of the window pane 1 onto a layer of black enamel or the like (not shown) so that neither the heat conductors 11, 12 nor the contact areas 13 nor any other parts of the electrical connector unit can be seen from the outside.

A pair of flat flexible metallic conductors 20 is in electrical contact with the two contact areas 13 and serves to supply "power from a battery (not shown) of the vehicle to the heating grid. Typically one of the conductors 20 is con- nected to the positive pole and the other to the negative pole of the battery. The metallic conductors 20 consists preferably of a thin metal band, made for example of stainless steel or any suitable alloy. The electrical contact to the contact areas 13 is preferably achieved by soldering, however, other methods like a metallic glue or spot-welding are also conceivable.

In order to avoid any short circuits, the metal bands 20 are integrated into or encompassed by a thin foil 21 of an isolating material. This is schematically shown in Fig. 2. The thickness of the band 20 and the foil 21 is for the sake of clarity greatly enlarged. In reality the thickness is preferably less than a fraction of a millimeter. Further, Fig. 2 shows for simplicity only one group 11 of heat conductors 11 and only one contact area 13.

Preferably, a polyimide foil (available from DuPont under the trade name Kapton) is used. Kapton has excellent dielectric properties, a high tensile strength and can resist temperatures of up to 400°C. This allows the use of a very thin foil 21 and at the same time to pass high currents of several amps through the metal bands 20. Although polyimide is preferred, other material might be used as well.

In order to maximize the mechanical stability of the attachment of the conductors 20 to the window pane 1 and to reduce the risk of any damages to the connector unit during the mounting of the window pane 1 to the body of the car (or any preparatory steps) the foil 21 with the integrated metal bands 20 is preferably guided below the glue bead 30. This glue bead 30 is generally arranged along the rim of the window pane 1 and serves to attach the window pane 1 to a surrounding frame (not shown) of the body of the car. The glue bead 30 might be combined with a plastic profile (not shown) which serves as a seal or the like and also extends along the rim of the window pane 1.

As a result of the arrangement below the glue bead 30, the foil 21 with the metal bands 20 extends from the contact area 13 preferably parallel to the surface of the pane 1, which leads to a minimal elevation of the connector unit 10 according to the invention.

Further, the glue bead 30 stabilizes the attachment, i.e. the solder connection, between the metal bands 20 and the contact areas 13, since any tensile load on the foil 21 and the metal bands 20, as for example indicated by the arrow in Fig. 2, is taken up by the glue bead 30. Preferably, the section of the foil 21 extending between the contact area 13 and the glue bead 30 is fixed, for example by means of an double sided adhesive tape, to the surface of the window pane 1. This further protects the electric interconnection between the metal bands 20 and the contact areas 13 against any mechanical damages.

The flexibility of the metal bands 20 and the surrounding foil 21 allows to arrange them around the rim of the window pane 1, as schematically indicated by the dashed arrow in Fig. 2. Thus, there is no need for any additional duct through the body of the vehicle to the battery which is typically arranged under the hood of the vehicle.

In order to facilitate the connection to standard electrical components a converter 40 is attached to the outer end of the metal bands 20, which transforms the metal bands 20 into two standard cables 50, which can be equipped with any ordinary type of plug. In case the above described elec- trical connector 10 is used for an antenna or other electronic devices, the converter 40 may also include suitable signal processing devices like for example pre-amplifiers or the like.

Claims

1. Electrical connector unit (10) for the electrical connection of conducting elements (11, 12) on the inner side of a window pane (1) of a motor vehi- cle, in particular the windscreen, comprising:

a. at least one contact area (13) on the inner surface of the window pane (1);

b. at least one connector (20) attached to the contact area and electrically isolated by an isolation (21), wherein

c. the combined thickness of the connector (20) and the isolation (21) is less than a fraction of a millimeter.

2. Electrical connector unit (10) according to claim 1, wherein the isolation 21 and the connector 20 are arranged below a glue bead 30 and/or seal arranged on the window pane (1).

3. Electrical connector unit (10) according to claim 1 or 2, wherein the connector (20) is soldered to the contact area (13).

4. Electrical connector unit (10) according to any of the claims 1 to 3, wherein the connector (20) comprises a thin flexible metal band (20).

5. Electrical connector unit (10) according to claim 4, wherein the isolation (21) comprises a thin polyimide foil (21).

6. Electrical connector unit (10) according to claim 4 or 5, wherein at least two contact areas (13) and at least two metal bands (20) are provided which are integrated into a common isolation (21).

7. Electrical connector unit according to claim 6, wherein the section of the isolation (21) extending between the contact areas (13) and the glue bead (30) or seal is attached to the window pane (1).

8. Electrical connector unit (10) according to any of the claims 1 - 7, wherein a converter for converting the at least one conductor (20) into a standard cable (50) is provided.

9. Electrical connector unit (10) according to any of the claims 1 - 8, wherein the conductor (20) is capable to conduct a current of several Amperes.

10. Window pane (1), in particular windscreen of a vehicle, with conducting elements (11, 12) electrically connected to an external circuit by means of an electrical connector unit (10) according to one of the claims 1 - 9.