The present invention relates to a windscreen wiper device comprising an elongated wiper blade of the flat blade type made of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade includes at least one groove, in which groove a longitudinal elastic strip is disposed, which wiper blade 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 a free end thereof, and wherein said

windscreen wiper device comprises a washing unit to be activated having at least one nozzle for spraying a washing liquid onto said windscreen to be wiped. Preferably, said oscillating arm can be pivotally connected to said

connecting device with the interposition of a joint part.

In the framework of the present invention the following is noted. Said connecting device, also called "connector", is preferably made of plastic. Said connector is preferably made in one piece, also called a "one piece connector".

Also the joint part, also called "spacer", is preferably made of plastic. Said joint part acts as a spacer interposed between said connecting device and said oscillating arm. The wiper blade being preferably made of an elastomer material, such as rubber, is particularly made through extrusion.

Particularly, 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. Said longitudinal groove is preferably a central longitudinal groove accommodating said longitudinal strip. Said longitudinal strip is also called a "flexor". Said connecting device is preferably fixedly connected to the longitudinal strip (s) particularly through a welding, brazing ("soldering") , gluing or clamping operation or with the help of a pin inserted through said connecting device and said longitudinal strip (s) . In the alternative or in addition thereto, said connecting device is clamped onto the flexible material of the wiper blade, particularly in case the latter is equipped with a central longitudinal groove for the carrier element. Preferably, said connecting device and said joint part are provided with mutually cooperating pivot means for pivotally connecting said joint part to said connecting device. All the above preferred features of the present invention can be used alone or in combination with any other feature (s), as a skilled person would appreciate.

A windscreen wiper device with a wiper blade of the "flat blade type" is generally known. In such a wiper blade of the "flat blade type" no use is made of several yokes pivotally connected to each other, but wherein the wiper blade is biased by the longitudinal elastic strip (functioning as an elastic carrier element) , as a result of which it exhibits a specific curvature. Usually, washing liquid is sprayed from a nozzle near a bonnet of a vehicle onto the wiped

windscreen. A source for said washing liquid, such as a water source or reservoir, a pump, as well as an electricity source, such as a battery, are preferably located under a bonnet of the car involved. A disadvantage of a nozzle fixedly mounted on (or below) a bonnet of a car for spraying a washing liquid onto the car' s windscreen to be wiped is the following. In practice it has become apparent that the windscreen cannot effectively be cleaned, as the nozzle emits the washing fluid thereon at a large distance relative to the windscreen, so that a relatively large amount of the washing fluid does not effectively reach a wiping pattern on the windscreen to be wiped. Further, it has become apparent that in the prior art a large amount of liquid (consumption) is required in an attempt to clean the windscreen to be wiped. Further, if the washing fluid is spread onto the car' s body instead of onto the windscreen to be wiped, it may damage the car. Indeed, ethanol, methanol and other components of the washing fluid are believed to have a corrosive effect on paint, rubber, car wax and plastics, for example .

It is an object of the invention to obviate these

disadvantages, in the sense that at minimum costs - without using complex machinery and additional tools - a simple windscreen wiper device is proposed to effectively clean a windscreen to be wiped, wherein less washing liquid is required to clean the windscreen to be wiped.

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 said washing unit comprises a valve device arranged for

intermittently disposing a washing liquid during a

predefined period of time onto said windscreen to be wiped upon a single activation of said washing unit. The washing unit is preferably activated manually, i.e. by hand (of the driver) . Hence, the washing unit - upon a single activation thereof - does not continuously spray the washing fluid onto the windscreen to be wiped, but instead sprays shots of said washing liquid, i.e. discontinuously, onto said windscreen to be wiped. Tests have shown that, surprisingly and

unexpectedly, the windscreen can thus be cleaned in an efficient manner, using less washing liquid. Preferably, said oscillating arm is provided with said nozzle. In the alternative, said wiper blade is provided with said nozzle. By connecting the nozzle directly to the oscillating arm or directly to the wiper blade wiper, the nozzle is not only fixed thereto in a reliable and

controllable manner, although detachably in case of repair or replacement of the nozzle, but the nozzle may also be hidden from the outside and thus invisible for a driver and people outside. Further, by connecting the nozzle directly to the oscillating arm or directly to the wiper blade wiper, the nozzle is located at a very small distance relative to the windscreen to be wiped and is allowed to directly follow any oscillatory movement of the windscreen wiper arm, so that the washing fluid exiting the nozzle can be effectively sprayed thereon, with all positive consequences involved as to effective cleaning of the windscreen to be wiped and safe visibility for a driver. Finally, by connecting the nozzle directly to the oscillating arm or directly to the wiper blade wiper, damage of (parts of) the car by the washing liquid is avoided, as the washing liquid does not reach the car's body.

In the alternative, the oscillating arm and the wiper blade may each be provided with a nozzle of the washing unit. In the alternative, the oscillating arm comprises two nozzles. In these cases the washing unit includes a first nozzle in combination with a second nozzle for spraying a washing liquid onto the windscreen to be wiped. Hence, in that case the washing liquid is sprayed from at least two locations onto the windscreen to be wiped, namely washing liquid exiting from the first nozzle connected to the oscillating arm, as well as washing liquid exiting from the second nozzle connected to the wiper blade or to another location on the oscillating arm. Thus, the windscreen can be cleaned efficiently over a very large wiping area thereof,

particularly at high speeds. In that case, the first and second nozzles are preferably connected to only one inlet for the washing fluid, so that the first and second nozzles are in liquid contact with each other.

Preferably, said oscillating arm at one end thereof is arranged to be pivotally connected to a mounting head mounted on a drive shaft, and wherein said oscillating arm at another end thereof is arranged to be pivotally connected to said elongated wiper blade to be placed in abutment with a windscreen to be wiped. Said mounting head is usually fixed for rotation to said 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 flat 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.

It is noted that the present invention is not restricted to cars, but also refers to rail coaches and other (fast) vehicles .

In a preferred embodiment of a windscreen wiper device in accordance with the invention said valve device is arranged for periodically spraying a washing liquid onto said

windscreen to be wiped upon a single activation of said washing unit with a predetermined duty cycle and with a predetermined frequency. Particularly, said duty cycle is determined between 25 and 75%. More in particular, said duty cycle is 50%.

In another preferred embodiment of a windscreen wiper device according to the invention said valve device is arranged for intermittently disposing shots of said washing liquid onto said windscreen to be wiped, and wherein said frequency is at least 2 shots during said predefined period of time.

In another preferred embodiment of a windscreen wiper device in accordance with the invention said nozzle comprises a spraying head detachably connected thereto. Preferably, said spraying head is detachably connected to said nozzle through a snapping connection.

In another preferred embodiment of a windscreen wiper device according to the invention said windscreen wiper device comprises said oscillating arm at one end thereof arranged to be pivotally connected to a mounting head mounted on a drive shaft and at another end thereof arranged to be pivotally connected to said wiper blade, wherein said oscillating arm can oscillate to-and-from between a first reversal position and a second reversal position, and wherein said oscillating arm is provided with said nozzle. Particularly, at least a part of said oscillating arm is made integrally from a single sheet material, wherein parts of said sheet material are folded outwardly to form legs of a U-shaped cross-section of said oscillating arm, and wherein one of said legs is connected to said nozzle. In another preferred embodiment of a windscreen wiper device in accordance with the invention said oscillating arm at said another end thereof is arranged to be pivotally- connected through a bayonet connection to said wiper blade.

In another preferred embodiment of a windscreen wiper device according to the invention said wiper blade comprises said nozzle. Preferably, said wiper blade comprises a central groove for said longitudinal elastic strip, wherein said central groove is defined by a bottom wall, a top wall and side walls, and wherein one of said side walls comprises said nozzle.

The invention will now be explained in more detail with reference to figures illustrated in a drawing, wherein:

Figures 1 and 2 are schematic views from a side (figure 1) and from below (figure 2), respectively, of a

windscreen wiper arm in a wiping position equipped with a wiper blade of the flat blade type; and

Figure 3 shows diagrammatically how said washing unit (with a valve device) is arranged for intermittently disposing a washing liquid during a predefined period of time onto said windscreen to be wiped upon a single activation of said washing unit .

Figures 1 and 2 show a windscreen wiper arm 1, particularly for automobiles, being able to oscillate to-and-from between a first reversal position and a second reversal position over a windscreen to be wiped (not shown) . The windscreen wiper arm 1 includes a wiper arm member 2 having a

substantially U-shaped cross-section, as well as a wiper rod 3. Said wiper arm member 2 at a first free end thereof is arranged to be pivotally connected to a mounting head (not shown) mounted on a drive shaft (not shown) The drive shaft is rotatable by a small motor alternately in a clockwise and in a counter-clockwise sense carrying said mounting head into rotation. Thus, in turn said mounting head draws said windscreen wiper arm 1 into rotation and thereby moves a flat blade 4 connected thereto. Said wiper arm member 2 at second free end thereof (opposite to its first free end) is rigidly connected to said wiper rod 3. The wiper arm member 2 is made integrally from a single sheet material, for example a metal, wherein parts of said sheet material are folded outwardly to form legs 5, 6 of the U-shaped cross- section of said wiper arm member 2, and wherein said legs 5, 6 of the U-shaped cross-section of said wiper arm member 2 are locally folded around said wiper rod 3 to form their rigid interconnection. As shown, the wiper rod 3 at a first free end thereof extends inside the U-shaped cross-section of the wiper arm member 2. The wiper rod 3 at a second free end thereof (opposite to its first free end) is connected to the flat blade 4 to be placed in abutment with a windscreen to be wiped.

As shown in figures 1 and 2, said windscreen wiper arm 1 is provided with a nozzle 7 for spraying a washing liquid onto the windscreen to be wiped. Said nozzle 7 is detachably snapped to said wiper rod 3 inside the U-shaped cross- section of the wiper arm member 2 to allow its repair and/or replacement. As shown, said nozzle 7 comprises two spraying openings 11, 12 for spraying the washing fluid onto the windscreen to be wiped. Further, said nozzle 7 comprises an inlet pipe 13 for conveying the washing liquid towards the nozzle 7. Figure 3 shows schematically that washing liquid is

intermittently disposed during a predefined period of time onto said windscreen to be wiped. The X-axis defines unit of time, while the Y-axis defines liquid amount per time unit. Shots of washing liquid are sprayed, wherein each shot lasts two seconds, and wherein three idle seconds are between adj acent shots . The present invention is not restricted to the embodiment shown in the figures, but extends also to other preferred variants falling within the scope of the appended claims.