Windscreen wiper device

Abstract: A windscreen wiper device comprising an elastic, elongated carrier element (4), as well as an elongated wiper blade (2) of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade (2) includes opposing longitudinal grooves (3) on its longitudinal sides, in which grooves (3) spaced-apart longitudinal strips (4) of the carrier element are disposed, wherein neighbouring ends of said longitudinal strips are interconnected by a respective connecting piece, which windscreen wiper device comprises a connecting device (7) for an oscillating wiper arm (8), as well as a spoiler (11), a special feature of which is that the spoiler (11) as a separate constructional element is detachably connected to the wiper blade (2).

Description: The 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 opposing longitudinal grooves on its longitudinal sides, in which grooves spaced-apart longitudinal strips of the carrier element are disposed, wherein neighboring ends of said longitudinal strips are interconnected by a respective connecting piece, which windscreen wiper device comprises a connecting device for an oscillating wiper arm, as well as a spoiler, and wherein said connecting device comprises clamping members, which engage round longitudinal sides of said longitudinal strips that face away from each other. Such a spoiler is also called an "air deflector". Such a windscreen wiper device is generally known. The prior art windscreen wiper device is in particular designed as a "yokeless" wiper device, wherein use is no longer 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. The spoiler and the wiper blade of the known windscreen wiper device are made in one piece. Windscreen wiper devices actually used on cars fitted with windscreens exhibiting some degree of curvature are sometimes subjected to a lifting effect at high speeds, which prevents the windscreen from being wiped correctly. This lifting effect is due to the following aerodynamic phenomenon. Streams of air along the car tend to escape vertically upwards along the axis of the car. Near the sides of the curved windscreen, however, the streams of air tend to pass horizontally along the sides. These streams of air create, mainly in the zones in which the windscreen wiper device meets them perpendicularly, a reduced pressure above the windscreen wiper device and an increased pressure between the windscreen and the windscreen wiper device. The resulting pressure, in spite of the mechanical pressure applied by the arm of the windscreen wiper device, causes the latter to lift away towards the front of the windscreen, thereby deteriorating the wiping pattern at higher driving speeds. A disadvantage of the known windscreen wiper device is that the spoiler and the wiper blade are made in one piece: every car has its own specific aerodynamic characteristics, so that a specific windshield wiper with an integrated spoiler has to be designed and manufactured for each type of car. Obviously this requires the use of complex machinery, tools, with all the expenses involved. A further drawback is that replacement (because of wear) of the wiper blade automatically implies the replacement of the spoiler. It is an object of the invention to obviate these disadvantages, in the sense that at minimum cost a windshield wiper device comprising a spoiler is proposed which can be mounted on all windshield wipers of different cars, without the use of complex machinery and additional tools being required. It is noted that the present invention is not restricted to windscreen wiper devices for cars, but that it also relates to windscreen wiper devices for rail coaches and all other (fast) vehicles. In order to accomplish that objective, a windscreen wiper device of the kind referred to in the introduction is characterized in that the spoiler comprises two subspoilers each on one side of the connecting device, wherein each subspoiler extends from the connecting device to a respective connecting piece, and wherein each subspoiler is detachably connected to the wiper blade or to the longitudinal strips of the carrier element. In particular, said connecting device and said clamping members are made in one piece. The use of two subspoilers ensures a great rigidity of the spoiler. German patent publication no. 198 56 300 (Robert Bosch GmbH) discloses a windscreen wiper device in accordance with the preamble of claim 1. The spoiler is made in one piece with the wiper blade thereof. Holders for maintaining backing strips in grooves of this known windscreen wiper device are shaped to have some air deflecting effect and are detachable. In one preferred embodiment of a windscreen wiper device according to the invention, said spoiler comprises clamping means which engage round longitudinal sides of said longitudinal strips that face away from each other. In another preferred embodiment said spoiler comprises clamping means which engage round longitudinal edges of said wiper blade that face away from each other. Preferably said spoiler and said clamping means are made in one piece. In another preferred embodiment of a windscreen wiper device according to the invention, said connecting pieces are clamping members, which form separate constructional elements. In particular, said connecting pieces are form-locked or force-locked to the adjacent ends of the longitudinal strips. In another preferred embodiment of a windscreen wiper device according to the invention, said connecting pieces are in one piece with said longitudinal strips. In another preferred embodiment of a windscreen wiper device according to the invention, at least said longitudinal strips are made of spring band material, preferably steel. The invention will now be explained in more detail with reference to figures illustrated in a drawing, wherein: figure 1 shows diagrammatically the flow of streams of air along the windscreen of a car; figures 2 is a diagram of a standard windscreen wiper device in a position parallel to the streams of air; figure 3 is a cross-section of the same windscreen wiper device, but in a position at right angles to the streams of air; figure 4 illustrates the forces due to the tangential streams of air acting on the standard windscreen wiper blade; figures 5 and 6 show a schematical and a perspective view, respectively, of a windscreen wiper device according to two preferred embodiments of the invention; and figure 7 is a total perspective, schematic view of the windscreen wiper device of figures 5 and 6. Figure 1 shows a perspective view of the front portion of a car provided with a curved windscreen A, together with the direction of flow of the streams of air, the latter passing the vehicle upwards and along the sides. In a zone in which a windscreen wiper device of the usual standard form is positioned parallel to the streams of air, as shown in figure 2, nothing unusual occurs; on the other hand, in a zone as shown in figure 3, in which the streams of air flow practically at right angles to the direction of the windscreen wiper device, this air cannot flow along the glass because of the wiper blade, and thus creates an increase in pressure (indicated by the + sign ). Such an increased pressure also exists in the region of the hollow profile comprised between the flanges of the frame C directed towards the windscreen. These flanges create further obstacles to the flow of air and assist in maintaining the increased pressure. In addition, the streams of air which pass round the windscreen wiper device towards the upstream side tend to move away from the surface and create a reduced pressure zone (indicated by the - sign), as is well known. These two forces Fx and Fz (which can be compared with the drag and the lift acting on a wing section) have a resultant R which tends to lift the windscreen wiper device against the mechanical pressure applied by the arm (see figure 4). Figures 5 and 6 show a preferred variant of a windscreen wiper device 1 according to the invention. Said windscreen wiper device is built up of an elastomeric wiper blade 2, in the longitudinal sides of which opposing longitudinal grooves 3 are formed, and of longitudinal strips 4 made of spring band steel, which are fitted in said longitudinal grooves 3. Said strips 4 form 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). Neighbouring ends 5 of strips 4 are interconnected on either side of the windscreen wiper device 1 by means of connecting pieces 6 functioning as clamping members. In this embodiment, the connecting pieces 6 are separate constructional elements, which may be form-locked as well as force-locked to the ends 5 of strips 4. In another preferred variant, said connecting pieces 6 are in one piece with the strips 4 made of spring band steel. In the latter case said connecting pieces form transverse bridges for the strips 4, as it were. The windscreen wiper device 1 is furthermore built up of a connecting device 7 of plastic material for an oscillating wiper arm 8. Connecting device 7 comprises clamping members 9 that are integral therewith, which engage round longitudinal sides 10 of the strips 4 that face away from each other, as a result of which the connecting device 7 is firmly attached to the unit consisting of wiper blade 2 and strips 4. The oscillating wiper arm 8 is pivotally connected to the connecting device 7 about a pivot axis near one end. Both preferred embodiments of figures 5 and 6 according to the invention comprise a spoiler 11 including two separate subspoilers 12 being detachably connected to the wiper blade 2 on opposite sides of the connecting device 7. The subspoilers 12 are made of an elastomeric material, rubber for example, and they are provided with clamping means 13 made in one piece therewith. In the preferred embodiment of figure 5 the clamping means 13 engage round longitudinal sides 10 of the longitudinal strips 4 that face away from each other, whereas in the embodiment of figure 6 the clamping means 13 engage around longitudinal laterally extending edges 14 of the wiper blade 2 that face away from each other. Of course, it is also possible for the clamping means to engage round other longitudinal laterally extending edges 15 of the wiper blade 2 that face away from each other. Figure 7 shows a total perspective, schematic view of the windscreen wiper device of figures 5 and 6, wherein corresponding parts have been designated with the same reference numerals. The invention is not restricted to the variants as shown in the drawing, but it also extends to other embodiments that fall within the scope of the appended claims.

Claims: A windscreen wiper device (1) comprising an elastic, elongated carrier element, as well as an elongated wiper blade (2) of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade (2) includes opposing longitudinal grooves (3) on its longitudinal sides, in which grooves spaced-apart longitudinal strips (4) of the carrier element are disposed, wherein neighbouring ends of said longitudinal strips (4) are interconnected by a respective connecting piece (6), which windscreen wiper device (1) comprises a connecting device (7) for an oscillating wiper arm (8), as well as a spoiler (11), and wherein said connecting device (7) comprises clamping members (9), which engage round longitudinal sides (10) of said longitudinal strips (4) that face away from each other, characterized in that the spoiler (11) comprises two subspoilers (12) each on one side of the connecting device (7), wherein each subspoiler (12) extends from the connecting device (7) to a respective connecting piece (6) at one end of the wiper device, and wherein each subspoiler (12) is detachably connected to the wiper blade (2) or to the longitudinal strips (4) of the carrier element. A windscreen wiper device according to claim 1, wherein said spoiler (11) comprises clamping means (13), which engage round longitudinal sides (10) of said longitudinal strips (4) that face away from each other. A windscreen wiper device according to claim 1 or 2, wherein said spoiler (11) comprises clamping means (13) which engage round longitudinal edges (14,15) of said wiper blade (2) that face away from each other. A windscreen wiper device according to claim 2 or 3, wherein said spoiler (11) and said clamping means (13) are made in one piece. A windscreen wiper device according to any one of the preceding claims 1 - 4, wherein said connecting pieces (6) are clamping members, which form separate constructional elements. A windscreen wiper device according to claim 5, wherein said connecting pieces (6) are form-locked or force-locked to the adjacent ends of said longitudinal strips (4). A windscreen wiper device according to any one of the preceding claims 1 - 4, wherein said connecting pieces (6) are in one piece with said longitudinal strips (4). A windscreen wiper device according to any one of the preceding claims 1 - 7, wherein at least said longitudinal strips (4) are made of spring band material. A windscreen wiper device according to any one of the preceding claims 1 - 8, wherein said connecting device (7) and said clamping members (9) are made in one piece.

Inventors: BOLAND XAVIER, GENET SOPHIE, HENIN PIERRE, BOLAND, XAVIER, GENET, SOPHIE, HENIN, PIERRE
Applicants: FEDERAL MOGUL SA, FEDERAL-MOGUL S.A.
Application year: 2001
Main classification: B60S1
IPC codes: B60S1