The present invention relates to a windscreen wiper device of the flat blade type, particularly for automobiles, comprising an elastic, elongated carrier element, as well as an elongated wiper blade of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade includes at least one longitudinal groove, in which groove at least one longitudinal strip of the carrier element is disposed, which windscreen wiper device comprises a connecting device for an oscillating arm, wherein said oscillating arm can be pivotally connected to said connecting device about a pivot axis near one end thereof. Particularly, said

oscillating arm can be pivotally connected to said connecting device with the interposition of a joint part. More in

particular, said wiper blade comprises a spoiler at a side thereof facing away from the windscreen to be wiped, wherein said wiper blade and said spoiler are preferably made in one piece through extrusion. Said longitudinal groove is

preferably a central longitudinal groove accommodating said longitudinal strip. Said longitudinal strip is also called a "flexor", while said connecting device is also indicated as a "connector". In the framework of the present invention said connector is preferably made in one piece, also called a "one piece connector" .

Such a windscreen wiper device is generally known. This prior art windscreen wiper device is designed as a so-called "flat blade" or "yokeless blade", wherein no use is made of several yokes pivotally connected to each other, but wherein the wiper blade is biassed by the carrier element, as a result of which it exhibits a specific curvature. The spoiler is also called an "air deflector". In cold conditions, such as in freezing conditions, for example in winter time, the wiper blade of the known windscreen wiper device may lose (some of) its flexibility, so that wiping properties are deteriorated. Also, said wiper blade may be blocked by snow and/or ice, resulting in a bad wiping performance. Also, snow and/or ice may prevent a wiping lip of said wiper blade to tumble over at each turning point of its oscillatory movement, leading to a significant "rattling" noise and chatter. Said wiping lip may even freeze unto a windscreen to be wiped resulting in a damage of the flexible material of the wiper blade.

The object of the invention is to provide an improved

windscreen wiper device. More in particular, the present invention aims to keep the wiping properties of the wiper blade thereof at a constant high level, also in cold

(freezing) conditions.

In order to accomplish that objective, a windscreen wiper device of the type referred to in the introduction is

characterized according to the invention in that an

electrically conductive coating is provided on at least a part of the longitudinal strip along at least a portion of its length in order to transfer electrically generated heat to the wiper blade upon applying a voltage to the electrically conductive coating. By applying the electrically conductive coating on a skin of the longitudinal strip it is possible to subject said coating to a voltage, so that said skin will heat up. The skin will then transfer its heat to other parts of the wiper blade in order to melt any snow and/or ice on the wiper blade. Particularly, in case the electrically conductive coating would have an electrical resistance of 6 or 12 Ohm, a voltage of 12 V or 24 V, respectively (dependent on the type of car) , would be applied thereon to heat up the skin of the longitudinal strip. Preferably, said electrically conductive coating is provided on a top surface of said longitudinal strip, i.e. the top surface of said longitudinal strip in use facing away from a windscreen to be wiped. Said coating is preferably provided along the entire length of said

longitudinal strip.

It is noted that the present invention is not restricted to the use of only one longitudinal strip forming the elastic carrier element that is particularly located in a central longitudinal groove of the wiper blade. Instead, said carrier element may also comprise two longitudinal strips, wherein said strips are disposed in opposite longitudinal grooves of the wiper blade. Said groove (s) may be closed at one outer end . Further, it is noted that in the invention use is made of a mounting head fixed for rotation to a shaft, wherein said shaft is rotatable alternately in a clockwise and in a counter-clockwise sense carrying said mounting head into rotation. Thus, in turn said mounting head draws said

connecting device into rotation and thereby moves said wiper blade. In the alternative, said mounting head is fixed for translation to a carriage, wherein said carriage can be translated alternately in a one linear direction and in another counter linear direction carrying said mounting head into translation. The present invention can therefore be used for circular or linear movement of said mounting head.

In a preferred embodiment of a windscreen wiper device in accordance with the present invention said longitudinal strip is made of an electrically conductive material, such as steel band, for applying a voltage to the electrically conductive coating. In the alternative or in addition thereto at least one electrically conductive wire is provided on said

longitudinal strip for applying a voltage to the electrically conductive coating, wherein said electrically conductive wire is in electrical contact with said electrically conductive coating. Particularly, two electrically conductive wires are provided on said longitudinal strip, wherein said electrically conductive wires are located near opposite exterior

longitudinal edges of said longitudinal strip. Said

electrically conductive wire(s) is/are inkjet on the

longitudinal strip. In another preferred embodiment said electrically conductive wire(s) is/are deposited with another method, such as serigraphy or paint rolling.

In the embodiments having (a) wire(s) the connecting device is preferably equipped with an electrical connection element to connect the wire(s) to a voltage generator.

In another preferred embodiment of a windscreen wiper device according to the present invention said electrically

conductive coating is an ink or paint containing Cu, Al or Ag, or any combination thereof. In an alternative, also other very conductive materials may be used.

As said earlier, said carrier element consists of one

longitudinal strip disposed in a central longitudinal groove of said wiper blade. In the alternative, said carrier element consists of two longitudinal strips disposed in opposing longitudinal grooves of said wiper blade.

The present invention also relates to a process for

manufacturing a windscreen wiper device of the flat blade type, comprising an elastic, elongated carrier element, as well as an elongated wiper blade of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade includes at least one longitudinal groove, in which groove at least one longitudinal strip of the carrier element is disposed, which windscreen wiper device comprises connecting device for an oscillating arm, wherein said oscillating arm is pivotally connected to said connecting device about a pivot axis near one end thereof, with the special feature that an electrically conductive coating is applied on at least a part of the longitudinal strip along at least a portion of its length in order to transfer

electrically generated heat to the wiper blade upon applying voltage to the electrically conductive coating.

The invention will now be explained more in detail with reference to figures illustrated in a drawing, wherein figure 1 is a perspective, schematic view of a preferred embodiment of a windscreen wiper device according to the invention; and

figure 2 shows a side view and a perspective view of a longitudinal strip in a wiper blade of the windscreen wiper device of figure 1 explaining the working

principle, according to another preferred embodiment as to how to heat a electrically conductive coating applied on the longitudinal strip in the wiper blade.

Figures 1 shows a preferred variant of a windscreen wiper device 1 according to the invention. Said windscreen wiper device 1 is built up of an elastomeric wiper blade 2

comprising a central longitudinal groove 3, wherein a longitudinal strip 4 made of spring band steel is fitted in said longitudinal groove 3. Said strip 4 forms a flexible carrier element for the rubber wiper blade 2, as it were, which is thus biassed in a curved position (the curvature in operative position being that of a windscreen to be wiped) . The windscreen wiper device 1 is furthermore built up of a connecting device 5 of metal or plastic for connecting an oscillating wiper arm thereto, with the interposition of a joint part 6. The oscillating wiper arm is pivotally connected to the connecting device 5 about a pivot axis near one end. The preferred embodiment of figure 1 according to the

invention comprises a spoiler or "air deflector" 7 which is made in one piece with the rubber wiper blade 2 and which extends along the entire length thereof. No end caps are used, but free ends of said wiper blade 2 are cut at an oblique angle. In the alternative end caps may be used.

Although not shown in figure 1, but fully understood by a skilled person, said oscillating arm is connected to a

mounting head fixed for rotation to a shaft driven by a small motor. In use, the shaft rotates alternately in a clockwise and in a counter-clockwise sense carrying the mounting head into rotation also, which in turn draws said oscillating arm into rotation and by means of said connecting device 5 moves said wiper blade 2. Said connecting device 5 further comprises an interior space 8 functioning as a water channel extending in longitudinal direction of said connecting device 5. During use said water channel 8 transports rain water therethrough. In other words, in use rain water is carried away from a first side of said connecting device 5 facing away from said free end of said oscillating arm to a second side of said connecting device 5 facing towards said free end of said oscillating arm. As a result of the oscillatory movement of said oscillating arm, in practice an over pressure relative to the environment exists at the location of said first side of said connecting device 5, while an under pressure relative to the environment is present at the location of said second side of said connecting device 5. Due to said over pressure and said under pressure rain water is "automatically" pressed through said water channel .

Said joint part 6 is detachably connected to said connecting device 5 by engaging protrusions 9 of said connecting device

5, at the location of said pivot axis, in co-axial recesses 10 provided in said joint part 6. As shown, said protrusions 8 extend outwards on either side of said connecting device 5. The joint part 6 comprises a resilient tongue 11 extending outwardly, while the oscillating arm has a U-shaped cross- section at the location of its connection to said joint part

6, so that the tongue 11 engages in an identically shaped hole provided in a base of said U-shaped cross-section. The

connecting device 5 with the wiper blade 2 is mounted onto the oscillating arm as follows. The joint part 6 being already clipped onto the connecting device 5 is pivoted relative to the connecting device 5, so that said joint part 6 can be easily slided on a free end of the oscillating arm. During this sliding movement the resilient tongue 11 is initially pushed in against a spring force and then allowed to spring back into said hole in said oscillating arm, thus snapping, that is clipping the resilient tongue 11 into the hole of the oscillating arm. This is a so-called bayonet-connection. The oscillating arm together with the joint part 6 may then be pivoted back in a position parallel to the wiper blade 2 in order to be ready for use. By subsequently pushing in again said resilient tongue 11 against the spring force (as if it were a push button) , the connecting device 5 and the joint part 6 together with the wiper blade 2 may be released from the oscillating arm. Dismounting the connecting device 5 with the wiper blade 2 from the oscillating arm is thus realized by sliding the connecting device 5 and the joint part 6 together with the wiper blade 2 in a direction away from the

oscillating arm. According to the invention an electrically conductive coating 12 is disposed onto the longitudinal strip 4 over the entire length of the wiper blade 2. In use a voltage of 12 or 24 V is applied across the electrically conductive coating 12 at both ends of the wiper blade 2, as shown. In figure 1 said

electrically conductive coating 12 is provided on a top surface of said longitudinal strip 4 made of an electrically conductive material, such as band steel, for applying a voltage to the electrically conductive coating 12.

Figure 2 shows a side view and a perspective view of the longitudinal strip 4 in the wiper blade 2 of the windscreen wiper device of figure 1 according to another preferred embodiment, explaining the working principle as to how to heat the electrically conductive coating 12 applied on the

longitudinal strip 4 of the wiper blade 2.

In the embodiment of figure 2 two electrically conductive wires 13 are provided on said longitudinal strip 4, wherein said electrically conductive wires 13 are located near

opposite exterior longitudinal edges of said longitudinal strip 4. Said electrically conductive wires 13 are in

electrical contact with said electrically conductive coating 12.

In the embodiment of figure 2 the longitudinal strip itself does not need to be made of an electrically conductive

material, such as band steel. In the embodiment of figure 2, the connecting device comprises an electrical connection element, to connect the electrically conductive wires 13 to a voltage generator. The invention is not restricted to the variants shown in the drawing, but it also extends to other preferred embodiments that fall within the scope of the appended claims.