Windshield wiper

Abstract: Windshield wiper comprising an oscillating arm and a frame (1) connected thereto receiving a wiping element (3), wherein the wiping element (3) is reinforced by at least one backing strip (4) located in a logitudinally extending recess (5) provided in the wiping element (3), wherein the frame (1) has at least one claw (2) which partially surrounds the backing strip (4), and the upper portion of the wiping element (3), wherein laterally extending means (8,10) are provided for retaining the backing strip (4), and wherein the backing strip (4) is flattened at a distance from its end (7) over a portion (6) of its length, in which portion (6) said means (8,10) are formed by a material removing operation.

Description: The invention relates to a windshield wiper comprising an oscillating arm and a frame connected thereto receiving a wiping element, wherein the wiping element is reinforced by at least one backing strip located in a longitudinally extending recess provided in the wiping element, wherein the frame has at least one claw which partially surrounds the backing strip and the upper portion of the wiping element, and wherein laterally extending means are provided for retaining the backing strip, which is preferably made of metal. The invention also refers to the backing strip as such, and to a process for manufacturing the windshield wiper. Such a windshield wiper is known from the German patent publication DE-A-32 08 749 (Valeo Systèmes d'Essuyage S.A.). With a windshield wiper of this type the wiping element is formed by a wiping blade made of an elastic material, such as rubber, said wiping blade being reinforced by two metal backing strips respectively inserted in two longitudinally extending recesses in said wiping blade. The frame of the known windshield wiper has several claws retaining the wiping blade and the two backing strips inserted therein in such a way, that a claw located at one end of the wiping blade locally fixates said blade, whereas the other claws allow a movement of the wiping blade in its longitudinal direction. Accordingly said wiping blade is permitted to follow any curvature changes of the windshield on which it lies. The laterally extending means of the known backing strip contain outwardly bent lips on the interior as well as on the exterior longitudinal edge of each backing strip. These lips serve to retain the backing strip in its position. A disadvantage of a windshield wiper according to the German patent publication referred to above is that, due to the complex construction of the backing strips used therein, it is difficult to manufacture and therefore rather expensive. As the outwardly bent lips on the interior longitudinal edge of each backing strip - due to their sharpness - deeply penetrate into the elastic material of the wiping blade, fractures therein occur during assembly and during any longitudinal movement mentioned earlier of the wiping blade. The present invention particularly relates to a windshield wiper comprising an oscillating arm and a frame connected thereto receiving a wiping element, wherein the wiping element is reinforced by at least one backing strip located in a longitudinally extending recess provided in the wiping element, wherein the frame has at least one claw which partially surrounds the backing strip and the upper portion of the wiping element, wherein laterally extending means are provided, whereby the backing strip is flattened at a distance from its end over de portion of its length. Such a windshield wiper is known from the European patent publication EP-A-0 465 095 (Trico-Folberth Ltd.). This prior art document refers to a stiffening structure for a windscreen wiper blade, wherein a pair of rails (25,27) are located longitudinally in side grooves in the blade rubber. To vary the flexibility, in the middle portion (49) the rails have a number of areas (51) having a reduced thickness. The change in thickness is achieved, for example, by a punching operation, i.e. by a flattening operation (page 2, lines 34 and 35). The term "punching" in that framework (page 3, line 34) is identical to the term "flattening" or "stamping". It is an object of the invention to obviate all prior art disadvantages, in the sense that at minimum costs - without using complex machinery - simple backing strips are proposed being easier to manufacture and having excellent retaining properties. It is noted that the present invention particularly relates to windshield wipers for motor cars, but is not restricted thereto; it refers also to rail coaches and all other (fast) vehicles. Furthermore, it is to be understood that the present invention also bears on a windshield wiper having an oscillating arm and a frame constructed as one part. Thereto, according to the present invention a windshield wiper mentioned above is characterized in that said flattened portion comprises said laterally extending means serving to retain the backing strip which are formed by a material removing operation, and said retaining means are arranged to cooperate on the one hand with said wiping element and on the other hand with said claw so as to retain said backing strip on the wiping element. By making use of a material removing operation, preferably punching instead of a bending operation as applied in the above German prior art document (DE-A-3 208 749), a very precise shape of the retaining means can be obtained. The strength and accurate shape of said means are very important, as the rubber wiping blade has a small dimension along the longitudinal recesses wherein the backing strips are inserted. Because the ends (tips) of the backing strip are not flattened, the shape of the retaining means can be accurately controlled. In an embodiment of a windshield wiper according to the invention flattening the backing strip and removing the material is carried out in one operation. As a result, the accuracy with which the shape of the means for retaining the back strip is manufactured, is increased. In a further embodiment of a windshield wiper according to the invention the material removing operation is a punching operation. In another preferred embodiment the operation is a cutting/sawing operation. In a further embodiment of a windshield wiper according to the invention the means comprise at least one tooth extending laterally from the interior longitudinal edge of the backing strip, said tooth retaining the backing strip on the wiping element. In a further embodiment of a windshield wiper according to the invention the means comprise at least one stop extending laterally from the exterior longitudinal edge of the backing strip, said stop retaining the backing strip on the claw and, as a result, on the wiping element. In another preferred embodiment the means comprise two stops located on opposite sides of the claw, respectively. The invention furthermore refers to a backing strip suitable for use in a windshield wiper according to the invention, as claimed in claim 8. Finally, the invention relates to a process for manufacturing a windshield wiper according to the invention, comprising the steps of flattening the backing strip at a distance from its end over a portion of its length; and carrying out a material removing operation for forming said means in said portion. Preferably, the above process steps are carried out in one operation. Further objects and effects of the invention will become apparent from the following detailed description taken in conjunction with the drawings, in which figure 1 shows a perspective view of a wiping blade with two backing strips according to the invention; figure 2 is a top view of a backing strip of figure 1; figure 3a shows a top view of a flattened portion of a backing strip according to the invention, whereas figures 3b, 3c and 3d refer to various embodiments for the retaining means, seen from above; figure 4 illustrates a cross-sectional view (a) of a wiping blade using a backing strip according to figure 3c, as well as a sectional view (b) along line A-A; and figure 5 corresponds to figure 4, on the understanding that it relates to an embodiment wherein only one backing strip according to the invention is used. Figure 1 shows a perspective view of a part of a windshield wiper according to the invention, representing a frame 1 having several claws 2 of which only one is depicted, which claws 2 partially surround the upper portion of a wiping blade 3 and two backing strips 4 inserted in longitudinally extending recesses 5 provided in the wiping blade 3. The wiping blade 3 and the backing strips 4 are preferably made of rubber and metal, respectively. According to the invention both backing strips 4 are flattened over a portion 6 of their length, in such a way that the end (tip) 7 of each backing strip 4 maintains its normal (non-flattened) thickness. Each flattened portion 6 comprises means for retaining the backing strip 4, which means consist of: two teeth 8 extending laterally from the interior longitudinal edge 9 of the backing strip 4, said teeth 8 retaining the backing strip 4 on the wiping blade 3; and two stops 10 extending laterally from the exterior edge 11 of the backing strip 4, wherein the stops 10 retain the backing strip 4 on the claw 2 and, as a result, on the wiping blade 3. As can be seen from figure 2, each tooth 8 preferably has the form of a swallow tail. In another preferred embodiment the swallow tail has a top angle of 60°. Figure 3a illustrates the flattened portion 6 of the backing strip 4 of figure 2, wherein the tip 7 of the backing strip 4 remains unflattened. Figures 3b, 3c and 3d represent preferred embodiments of the teeth 8 extending laterally from the interior longitudinal edge of the backing strip 4, which teeth 8 in fact function as cramps. In figure 4a a cross-sectional view of the wiping blade 3 of figure 1 is shown, whereas figure 4b represents a sectional view along line A-A. It is noted that in figure 4b backing strips 4 according to figure 3c are depicted. Figures 5a and 5b correspond to figures 4a and 4b respectively, on the understanding that the wiping blade 3 is reinforced by only one backing strip 4 located in a longitudinally extending recess centrally provided in the wiping blade 3. This specific backing strip 4 is provided on its interior and exterior edge with two stops 10, respectively to fixate the backing strip 4 on the claw 2 and - as a consequence - on the wiping blade 3. The present invention makes it possible to provide backing strips being easy to manufacture and having excellent retaining properties vis-à-vis the wiping blade, the latter being due to the very accurate shape and strength of the retaining means provided thereon.

Claims: Windshield wiper comprising an oscillating arm and a frame connected thereto receiving a wiping element (3), wherein the wiping element (3) is reinforced by at least one backing strip (4) located in a longitudinally extending recess (5) provided in the wiping element (3), wherein the frame has at least one claw (2) which partially surrounds the backing strip (4) and the upper portion of the wiping element (3), wherein laterally extending means are provided, whereby the backing strip (4) is flattened at a distance from its end over a portion (6) of its length, characterized in that said flattened portion (6) comprises said laterally extending means (8,10) serving to retain the back strip (4) which are formed by a material removing operation, and said retaining means (8,10) are arranged to cooperate on the one hand with said wiping element (3) and on the other hand with said claw (2) so as to retain said backing strip (4) on the wiping element (3). Windshield wiper according to claim 1, wherein flattening the backing strip (4) and removing the material is carried out in one operation. Windshield wiper according to claim 1 or 2, wherein the material removing operation is a punching operation. Windshield wiper according to claim 1 or 2, wherein the material removing operation is a cutting/sawing operation. Windshield wiper according to any of the preceding claims 1 through 4, wherein the means (8,10) comprise at least one tooth (8) extending laterally from the interior longitudinal edge (9) of the backing strip (4), said tooth (8) retaining the backing strip (4) on the wiping element (3). Windshield wiper according to any of the preceding claims 1 through 5, wherein the means (8,10) comprise at least one stop (10) extending laterally from the exterior longitudinal edge (11) of the backing strip (4), said stop (10) retaining the backing strip (4) on the claw (2). Windshield wiper according tot claim 6, wherein the means comprise two stops (10) located on opposite sides of the claw (2), respectively. Backing strip (4) for use in a windshield wiper according to any of the preceding claims 1 through 7, which backing strip (4) is flattened at a distance from its end over a portion (6) of its length, wherein said flattened portion (6) comprises said laterally extending means (8,10) serving to retain the back strip (4) which are formed by a material removing operation, and said retaining means (8,10) are arranged to cooperate on the one hand with said wiping element (3) and on the other hand with said claw (2) so as to retain said backing strip (4) on the wiping element (3). Process for manufacturing a windshield wiper according to any of the preceding claims 1 through 7, comprising the steps of flattening the backing strip (4) at a distance from its end over a portion (6) of its length; and carrying out a material removing operation for forming said means (8,10) in said portion (6). Process according to claim 9, wherein the steps are carried out in one operation.

Inventors: ROSIERE ALEXANDRE JEAN, SAEDELAERE DIETER CECILIA DE, DE SAEDELAERE, DIETER CECILIA, ROSIERE, ALEXANDRE JEAN
Applicants: COOPER AUTOMOTIVE SA, COOPER AUTOMOTIVE S.A.
Application year: 1996
Main classification: B60S1
IPC codes: B60S1