The present invention relates to a windscreen wiper device 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 a longitudinal strip of the carrier element is disposed, which windscreen wiper device comprises a connecting device for an oscillating arm, wherein said oscillating arm is pivotally connected to said connecting device about a pivot axis near one end, with the interposition of a joint part, wherein said joint part is detachably connected to said connecting device by engaging protrusions of said connecting device, at the location of said pivot axis, in recesses provided in said joint part, wherein said joint part has an at least substantially U- shaped cross-section at the location of its connection to said connecting device, and wherein said joint part in each leg of said U-shaped cross-section is provided with a recess provided coaxially with said pivot axis.

The present invention also relates to a method for manufacturing this windscreen wiper device.

Such a windscreen wiper device is generally known. This prior art windscreen wiper device is designed as a "yokeless" wiper device or "flat blade", wherein no use is made of several yokes pivotally connected to each other, but wherein the wiper blade is biased by the carrier element, as a result of which it exhibits a specific curvature. In practice it has become apparent that, during use of the known windscreen wiper device, high forces are exerted on the connection between the connecting device and the oscillating arm. As a consequence thereof the wiper blade may get loose from the oscillating arm.

The object of the invention is to provide a windscreen wiper device, wherein the connecting device and the oscillating arm are connected in an improved, reliable and secure manner, using a minimum of parts.

Thereto, a windscreen wiper device of the type referred to in the preamble is characterized according to the invention in that each leg of said U-shaped cross-section of said joint part is provided with a downwardly extending, resilient finger, wherein said fingers are allowed to bend inwardly upon sliding said joint part in said oscillating arm for connecting said joint part and said oscillating arm through a snapping operation. In other words, a connection is realized using three parts (namely the connecting device, the joint part and the oscillating arm), wherein only the plastic joint part is plastically or elastically deformed for interconnecting the wiper blade, the joint part and the oscillating arm. First, the legs of the U-shaped cross- section of the plastic joint part are plastically or elastically deformed by preferably clipping/snapping the joint part onto the wiper blade, wherein the protrusions on the connecting device are preferably clipped/snapped into the recesses of the joint part. In the alternative, the joint part is slided on to the connecting device. Subsequently, the unit consisting of the wiper blade and the joint part is connected to the oscillating arm by clipping/snapping said unit onto the oscillating arm, wherein said downwardly extending, resilient fingers of the joint part are plastically or elastically deformed. Preferably, the protrusions on said connecting device extend outwards on either side thereof, wherein said protrusions and said recesses provided in said joint part are cylindrical .

Preferably, in use the connecting device and the joint part connected thereto are entirely positioned, at the location of their connection to the oscillating arm, within the U- shaped cross-section of the oscillating arm. Consequently, any color changes of the connecting device and/or the joint part due to ageing, wear and/or the exposure thereof to UV- light, rain, ice, high or low temperatures are not visible from the outside.

In one preferred embodiment of a windscreen wiper device in accordance with the invention each finger is bendable between a inward position upon slidingly mounting said oscillating arm over said joint part, and an outward position upon snappingly interconnecting said joint part and said oscillating arm.

In another preferred embodiment of a windscreen wiper device according to the invention said oscillating arm has an at least substantially U-shaped cross-section at the location of its connection to said joint part, wherein each finger at its end comprises a sidewardly and outwardly bended edge integral therewith, said edges engaging around longitudinal edges of the legs of the U-shaped cross-section of said oscillating arm. Preferably, each finger comprises at least one sidewardly and outwardly extending rib/tooth, and wherein said rib snappingly engages into a correspondingly shaped recess in a corresponding leg of the U-shaped cross- section of said oscillating arm.

Particularly, said wiper blade is movable between a working position, wherein said fingers are not allowed to bend inwardly so as to retain said wiper blade onto said oscillating arm, and a service position wherein said fingers are allowed to bend inwardly so as to release said wiper blade from said oscillating arm in the service positioning. In other words, in said working position the fingers abut the longitudinal strips of the wiper blade, so that the fingers cannot be bent inwardly. Thus, the wiper blade is retained onto the oscillating arm in the working position. However, through a slight rotational movement of said wiper blade, the fingers can be bent inwardly by hand so as to release the wiper blade from the oscillating arm in the service position.

In another preferred embodiment of a windscreen wiper device in accordance with the invention said oscillating arm has an at least substantially U-shaped cross-section at the location of its connection to said joint part, wherein the legs of said U-shaped cross-section of said joint part abut against corresponding legs of the U-shaped cross-section of said oscillating arm. Particularly, each leg of said U- shaped cross-section of said joint part is located inside a correspondingly shaped recess in a corresponding leg of the U-shaped cross-section of said oscillating arm. More in particular, each leg of said U-shaped cross-section of said joint part is provided with opposing, sidewardly and outwardly extending protrusions at the outer contour thereof in order to block any relative movement in longitudinal direction between said wiper blade and said oscillating arm.

In another preferred embodiment of a windscreen wiper device according to the invention said wiper blade can be released from said oscillating arm by a relative rotational movement between said wiper blade and said oscillating arm, and by a subsequently pushing said fingers of said joint part inwardly.

The present invention also relates to a method for manufacturing a windscreen wiper device 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 on longitudinal groove, in which groove a longitudinal strip of the carrier element is disposed, which windscreen wiper device comprises a connecting device for an oscillating arm, wherein said oscillating arm is pivotally connected to said connecting device about a pivot axis near one end, with the interposition of a joint part, wherein said joint part is detachably connected to said connecting device by engaging protrusions of said connecting device, at the location of said pivot axis, in recesses provided in said joint part, wherein said joint part has an at least substantially U-shaped cross-section at the location of its connection to said connecting device, and wherein said joint part in each leg of said U-shaped cross- section is provided with a recess provided coaxially with said pivot axis, with the special feature that each leg of said U-shaped cross-section of said joint part is provided with a downwardly extending, resilient finger, wherein said fingers are allowed to bend inwardly upon sliding said oscillating arm over said joint part for connecting said joint part and said oscillating arm through a snapping operation .

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

figure 1 are perspective, schematic views of a preferred embodiment of a windscreen device according to the invention, wherein only is shown the part thereof where an oscillating arm is connected to a wiper blade; figure 2 shows a first step for fitting the wiper blade and the oscillating arm of figure 1 together, using a joint part; figure 3 are perspective, schematic views of the wiper blade and the joint part of figure 2 fitted together; figure 4a is a perspective, schematic view of the wiper blade and the oscillating arm of figure 1 fitted together, seen from beneath, whereas figure 4b is a perspective, schematic view of the oscillating arm of figure 1, again seen from beneath; figures 5a through 5c are several cross-sectional views (a,b) and a longitudinal sectional view (c) of parts shown in figure 1, and figure 6 corresponds to figure 5a, but showing how said wiper blade may be released from said oscillating arm.

Figure 1 partly shows a preferred variant of a windscreen wiper device 1 according to the invention, wherein the part shown refers to the interconnection between an elastomeric wiper blade 2 and an oscillating arm 3. Said windscreen wiper device 1 is built up of said elastomeric wiper blade 2, in the longitudinal sides of which opposing longitudinal grooves 4 are formed, and of longitudinal strips 5 made of spring band steel, which are fitted in said longitudinal grooves 4 (see figure 6) . Said strips 5 form a flexible carrier element for the wiper blade 2, as it were, which is thus biased in a curved position (the curvature in operative position being that of a windscreen to be wiped) . Neighboring ends of the strips 5 are interconnected on either side of the windscreen wiper device 1 by means of connecting pieces (not shown) functioning as clamping members. The connecting pieces are separate constructional elements, for example, which may be form-locked ("positive locking" or "having a positive fit") or force-locked to the ends of the strips 5. In another preferred embodiment, said connecting pieces are in one piece with the strips 5 made of spring band steel. In the latter case said connecting pieces form transverse bridges for the strips 5, as it were.

The windscreen wiper device 1 is furthermore built up of a connecting device 6 of plastic material for said oscillating arm 3 (see figure 2) . Alternatively, the connecting device 6 may also be made of metal, such as steel or aluminum. The connecting device 6 is fixedly connected to said strips 5. Said connecting device 6 is particularly welded, brazed ("soldered"), glued or clamped onto said strips 5. The oscillating arm 3 is pivotally connected to said connecting device 6 about a pivot axis near one end, as will be described hereunder.

With reference to figure 2 the connecting device 6 comprises two cylindrical protrusions 7 extending outwards on either side of said connecting device 6. Alternatively, said protrusions may have a spherical or frusto-conical shape. These protrusions 7 pivotally engage in identically shaped cylindrical recesses 8 of a plastic joint part 9. In the alternative the recesses 8 may have a non-closed shape (i.e. open circumference) . Said protrusions 7 act as bearing surfaces at the location of a pivot axis in order to pivot the joint part 9 (and the oscillating arm 3 attached thereto) about said pivot axis near one end of the oscillating arm 3. The protrusions 7 are preferably in one piece with the connecting device 6; in the alternative, the protrusions 7 are part of a single pivot pin perpendicular to the connecting device 6. The joint part 9 has a U-shaped cross-section having a base 10 and legs 11, at the location of its connection to said connecting device 6, In fact, the legs 11 of the U-shaped cross-section of said joint part 9 comprise two resilient, that is elastically deformable fingers 12 integral therewith and extending downwardly, so that said fingers 12 are allowed to bend inwardly upon sliding said oscillating arm 3 over said joint part 9 for connecting said joint part 9 and said oscillating arm 3 through a snapping or clipping operation. More in particular, each finger 12 is hinged between an inward position upon slidingly mounting said oscillating arm 3 over said joint part 9, and an outward position upon snappingly interconnecting said joint part 9 and said oscillating arm 3. As can be seen from figure 3, each finger 12 at its end comprises an edge 13 integral therewith and bended in sideward and outward direction. Hence, any relative movement in transversal direction between said wiper blade 2 and said oscillating arm 3 is blocked by said bended edges 13.

Referring to figures 1 and 4 said oscillating arm 3 has an at least substantially U-shaped cross-section at the location of its connection to said joint part 9 in such a way that said connecting device 6 and said joint part 9 are entirely inside a base 14 and legs 15 of the U-shaped cross- section of said oscillating arm 3. As can be seen in figure 3, each finger 12 comprises a rib or tooth 16 extending in sideward and outward direction, so that said rib 16 snappingly engages into a correspondingly shaped recess 17 in a corresponding leg 15 of the U-shaped cross-section of said oscillating arm 3 (figure 4b) . In the position shown in figures 4a and 4b the legs 11 of said U-shaped cross-section of said joint part 9 abut against corresponding legs 15 of the U-shaped cross-section of said oscillating arm 3. As can be seen in figure 4b, in order to firmly accommodate the joint part 9 inside said oscillating arm 3, each leg 11 of said U-shaped cross-section of said joint part 9 is located inside a correspondingly shaped recess or deepening 18 in a corresponding leg 15 of the U-shaped cross-section of said oscillating arm 3.

Figures 5a through 5c are several cross-sectional views (a,b) and a longitudinal sectional view (c) of parts shown in figure 1, wherein corresponding parts have been designated with the same reference numerals. Each leg 11 of said U-shaped cross-section of said joint part 9 is equipped at the outer contour thereof with two pair of opposing protrusions 19,20; 21,22 extending in sideward and outward direction in order to block any relative movement in longitudinal direction between said wiper blade 2 and said oscillating arm 3. Said protrusions 19,20; 21,22 locally cooperate with correspondingly shaped parts of the inner contour of said recess/deepening 18, so that said joint part 9 is form-locked ("positive locking" or "having a positive fit") to the oscillating arm 3. With reference to figure 6 said wiper blade 2 can be released from said oscillating arm 3 from a working position, wherein release is not possible (figure 6a) to a service position, wherein release is possible (figure 6b) , and vice versa. This is realized by a slight relative rotational movement between said wiper blade 2 and said oscillating arm 3, and by subsequently pushing said fingers 12 of said joint part 9 inwardly by hand. As can be seen from figure 6, in the working position said strips 5 abut with their longitudinal outer edges the legs (11) of the U- shaped cross-section of said joint part (9) (see the encircled detail A in figure 6a) , while in the service position there exists a gap in between in the sense that the wiper blade 2 and the oscillating arm 3 are loose parts (see the encircled detail A in figure 6b) .

Although not depicted in the figures, it will be clear for a person skilled in the art that the oscillating wiper arm 3 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 the oscillating wiper arm 3 into rotation and by means of the connecting device 6 moves the wiper blade 2.

The invention is not restricted to the variants shown in the drawing, but it also extends to other embodiments that fall within the scope of the appended claims.