A wiper blade and a method of manufacturing a wiper blade

Abstract: A wiper blade, for example for a windscreen wiper device for a vehicle, comprising a metal yoke (3,4) which is attached to a metal carrier (1) in such manner as to be capable of pivoting movement about a pivot axis, with the interposition of a joint part (6) of plastic material, which is stationary with respect to said carrier (1), whereby both said carrier (1) and said yoke (3) have a substantially U-shaped cross-section at the location of their interconnection, and whereby said yoke (3) is positioned substantially within said carrier (1), with the interposition of said joint part (6), whereby said yoke (3) is in each leg of said U-shaped cross-section provided with a protrusion (11) at the location of said pivot axis, which protrusion (11) pivotally engages in said joint part (6).

Description: The invention relates to a wiper blade, for example for a windscreen wiper device for a vehicle, comprising a metal yoke which is attached to a metal carrier in such manner as to be capable of pivoting movement about a pivot axis, with the interposition of a joint part of plastic material, which is stationary with respect to said carrier, whereby both said carrier and said yoke have a substantially U-shaped cross-section at the location of their interconnection, and whereby said yoke is positioned substantially within said carrier, with the interposition of said joint part, whereby said yoke is in each leg of said U-shaped cross-section provided with a protrusion at the location of said pivot axis, which protrusion pivotally engages in said joint part. The material of the joint part is referred to as plastic, which include any synthetic material having some flexibility. A wiper blade of this type is usually provided with a plurality of yokes, in order to ensure that the wiper blade is in contact with the, usually curved, windscreen along its entire length. Each yoke is thereby pivoted to the end of a carrier in its central portion, which carrier itself may also be a yoke. The invention particularly relates to the manner in which the central portion of a yoke is pivoted to the end of a carrier. With a joint of this type said pivoting of the yoke must take place substantially without any friction, whilst the joint must be extremely wear resistant. During use of a wiper blade relatively great, varying forces are exerted on the pivoted joint, whilst the yoke keeps pivoting almost constantly. In order to enhance the durability of the joint it is known to make the joint part of plastic material and mount it between the yoke and the carrier in such a manner that the two parts, which move relative to each other and which are both made of a metal, do not come into contact with one another. EP-A-0412145 (WO-A-90/09300) describes a wiper blade whereby the carrier and the yoke are pivotally interconnected by means of a pivot pin, which is secured in the yoke and which can rotate in two holes provided coaxially in the carrier. In order to prevent the metal pivot pin, which rotates in the carrier, from coming into direct contact with the carrier, said carrier is provided with a plastic part which extends into the said holes of the carrier. The pivot pin rotates in the plastic part, therefore. EP-A-0631914 describes a wiper blade likewise comprising a pivot pin, whereby said pivot pin does not rotate in the plastic part, however, but is fixedly provided therein, so that the pivot pin, together with the plastic part, forms the joint part between the carrier and the yoke. The yoke thereby rotates with respect to the joint part. FR-A-2.491.847 discloses a wiper blade according to the preamble of claim 1. The object of the invention is to improve the wiper blade known from the above French patent publication (see especially figures 10 and 11) and therefore to provide a pivotable joint between the end of a carrier and the central portion of a yoke, whereby it is possible to realize a more reliable, more wear resistant construction comprising less parts. In order to accomplish that objective said carrier has two holes provided coaxially with said pivot axis, whereby a cylindrical portion of said joint part is provided through each of said holes and whereby said protrusion of said yoke extends into said cylindrical portion. This makes it possible to realize an effectively operating and reliable joint, whilst minimizing the number of parts. In particular it is possible to refrain from the use of a metal pivot pin. Furthermore the joint part is maximally supported by the carrier at the location of the bearing of the yoke by means of the protrusions. According to an embodiment of the invention said protrusions may be substantially cylindrical and preferably extend outwards on either side with respect to the yoke. A cylindrical protrusion may be made in a simple manner by means of a stamping operation during the manufacturing of the yoke. Since the protrusions extend outwards the two bearing supports of the yoke are spaced relatively far apart, as a result of which the forces exerted on said bearings are relatively small. According to a further embodiment of the invention the said holes are substantially cylindrical. The invention furthermore relates to a method of manufacturing a wiper blade as described above, wherein the carrier is provided with said joint part prior to positioning the legs of the U-shaped part of the carrier into substantially parallel relationship, whereby parts of said joint part, which abut against the carrier, are bent outwards, whereupon the carrier and the joint part are given their final shape after the yoke comprising the protrusions has been positioned within the joint part. As a result of this the deformation of the carrier into its final shape will cause the yoke to be locked in the joint part. In order to more fully explain the invention four embodiments of a joint part will be described hereafter with reference to the drawing. Figure 1 is a plan view of a wiper blade; Figure 2 is a side view of a wiper blade; Figure 3 shows an embodiment of the joint according to the invention; Figures 4-7 are elevational views of the joint part according to said embodiment; Figures 8-11 are sectional views of the joint part according to the said embodiment; Figures 12-15 show the assembly according to said embodiment. The embodiment is only schematically illustrated in the various Figures, wherein like parts are numbered alike. Figures 1 and 2 show the plan view and the side view of a wiper blade, which consists of a first yoke 1, which can be pivotally attached to an oscillating arm of a windscreen wiper device of a vehicle at the location of pivot axis 2. The first yoke 1 functions as the carrier of two secondary yokes 3, which secondary yokes function as the carriers 5 of four tertiary yokes 4. All yokes 3 are pivot-mounted in their respective carriers, so that a force exerted at the location of pivot axis 2 is distributed more or less evenly over the ends of the tertiary yokes 4, capable of being transferred to a rubber wiper means, which can be fitted on the ends 5 of the tertiary yokes 4. The pivoted joint between each yoke (3,4) and its respective carrier (1,3) is effected with the interposition of a joint part 6, which is made of plastic material. Figure 3 shows the illustrated embodiment to be described in more detail hereafter, and the joint between the carrier 1 (first yoke) and the yoke 3 (secondary yoke) of each part will be explained in more detail with reference to Figures 4-5. Said Figures only show the carrier 1 in sectional view at the location of hole 7, whilst yoke 3 is only shown in sectional view at the location of protrusion 11. Figures 4-15 show said embodiment, whereby Figures 4-7 are elevational views and Figures 8-11 are sectional views of the joint part 6. In this embodiment assembly takes place in that carrier 1 has not yet been given its final shape comprising a U-shaped cross-section when joint part 6 is being fitted. When the legs of said U-shaped cross-section are still in a position in which they extend slightly away from each other (Figure 12), joint part 6 is placed into carrier 1, and that in such a manner that cylindrical parts 13 of joint part 6 extend into recesses 7 of carrier 1 (Figure 13). Then yoke 3 is positioned within said assembly (Figure 14), after which carrier 1 is given its final shape by deformation of the material (Figure 15). Protrusions 11 thereby extend into holes 12 provided in the cylindrical parts 13 of joint part 6. In this embodiment the locking of joint part 6 with respect to yoke 3 is effected in that deformation of joint part 6 is prevented by carrier 1.

Claims: A wiper blade, for example for a windscreen wiper device for a vehicle, comprising a metal yoke (3) which is attached to a metal carrier (1) in such manner as to be capable of pivoting movement about a pivot axis, with the interposition of a joint part (6) of plastic material, which is stationary with respect to said carrier (1), whereby both said carrier (1) and said yoke (3) have a substantially U-shaped cross-section at the location of their interconnection, and whereby said yoke (3) is positioned substantially within said carrier (1), with the interposition of said joint part (6), whereby said yoke (3) is in each leg of said U-shaped cross-section provided with a protrusion (11) at the location of said pivot axis, which protrusion (11) pivotally engages in said joint part (6), characterized in that said carrier (1) has two holes (7) provided coaxially with said pivot axis, whereby a cylindrical portion (13) of said joint part (6) is provided through each of said holes (7) and whereby said protrusion (11) of said yoke (3) extends into said cylindrical portion (13). A wiper blade according to claim 1, characterized in that said protrusions (11) are substantially cylindrical. A wiper blade according to claim 1 or 2, characterized in that said holes (7) are substantially cylindrical. A vehicle provided with a windscreen wiper device comprising a blade according to any one of the preceding claims. A method of manufacturing a wiper blade according to any one of the claims 1 - 3, wherein said carrier (1) is provided with said joint part (6) prior to positioning said legs of the U-shaped part of the carrier (1) into substantially parallel relationship, whereby parts of said joint part (6) abutting against said carrier (1) are bent outwards, whereupon said carrier (1) and said joint part (6) are given their final shape after said yoke (3) comprising said protrusions (11) has been placed within said joint part (6).

Inventors: JANDIN PATRICE, JANDIN, PATRICE
Applicants: COOPER AUTOMOTIVE SA, COOPER AUTOMOTIVE S.A.
Application year: 1995
Main classification: B60S1
IPC codes: B60S1