NL2016036A

NL2016036A - Windscreen wiper device.

Info

Publication number: NL2016036A
Application number: NL2016036A
Authority: NL
Inventors: Boland Xavier
Original assignee: Federal Mogul Sa
Priority date: 2015-12-24
Filing date: 2015-12-24
Publication date: 2017-06-29
Also published as: NL2016036B1

Abstract

A windscreen wiper device of the flat blade type, comprising - a longitudinally extending wiper blade of a flexible material, said wiper blade including a spoiler portion, a wiping portion and a hinge portion integrally connected as one piece of said flexible material; - at least one carrier of a spring-like material operatively supporting and biasing said wiper blade into a predetermined configuration; - a connecting device for connection with a oscillating arm; wherein said spoiler portion of said wiper blade is provided with a microtextured surface, with the special feature that said microtextured surface includes a plurality of ribs extending in longitudinal direction of the wiper blade and protruding from said spoiler portion, wherein each rib has a cross-section in the form of a trapezium.

Description

WINDSCREEN WIPER DEVICE

The present invention relates to a windscreen wiper device of the flat blade type, comprising - a longitudinally extending wiper blade of a flexible material, said wiper blade including a spoiler portion, a wiping portion and a hinge portion integrally connected as one piece of said flexible material; - at least one carrier of a spring-like material operatively supporting and biasing said wiper blade into a predetermined configuration; - a connecting device for connection with a oscillating arm; wherein at least a portion of said wiper blade has a microtextured surface formed directly into said flexible material of said spoiler portion of said wiper blade.

Particularly, said oscillating arm can be pivotally connected to said connecting device with the interposition of a joint part. More in particular, 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 through extrusion. Said wiper blade preferably comprises a longitudinal groove for accommodating said carrier in the form of a longitudinal strip, wherein said longitudinal groove is preferably a central longitudinal groove for mounting said longitudinal strip therein. Said longitudinal strip is also called a "flexor", while said connecting device is also indicated as a "connector". In the framework of the present invention said connector is preferably made in one piece, also called a "one piece connector".

Such a windscreen wiper device is generally known. This prior art windscreen wiper device is designed as a so-called "flat blade" or "yokeless blade", wherein no use is made of several yokes pivotally connected to each other, but wherein the wiper blade is biassed by the carrier, as a result of which it exhibits a specific curvature. The spoiler is also called an "air deflector". US patent publication no. 2013/0125332 of the same Applicant discloses such a flat blade, wherein a microtextured surface is formed directly into said flexible material of said spoiler portion of said wiper blade. The microtexturing improves the down-force provided by the spoiler portion or reduces the aerodynamic drag of the wiper blade.

The object of the invention is to provide an improved windscreen wiper device. More in particular, the present invention aims to further improve the wiping properties of the wiper blade thereof at a constant high level.

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 microtextured surface includes a plurality of ribs extending in longitudinal direction of the wiper blade and protruding from said spoiler portion, wherein each rib has a cross-section in the form of a trapezium. Preferably, a longitudinally extending free edge of said wiping portion (in use contacting a windscreen to be wiped) does also not contain said microtextured surface. Said microtextured surface particularly extends along the entire length of said spoiler portion. In the alternative, said microtextured surface extends along a part of the length of said spoiler portion.

Particularly, said ribs each have a cross-section in the shape of an iscosceles trapezium. More in particular, a small base of said trapezium has a length varying between 30 and 60 pm, while a large base of said trapezium has a length varying between 70 and 120 pm. Even more in particular, a protruding height of said ribs varies between 60 and 80 pm, whereas the distance between middle longitudinal planes of adjacent ribs varies between 180 and 250 pm. Experiments have shown that very good wiping properties thus are obtained, whilst wear of the wiping portion is minimal.

In use, during each oscillatory movement of said oscillatory arm, rain water will be pressed against a side of said connecting device facing away from said free end of said oscillating arm, as said side of said connecting device has an over pressure relative to the environment as a result of an oscillatory movement of said oscillating arm. Hence, rain water accumulates at the location of said side of said connecting device resulting in the so-called "after spray" phenomenon, namely droplets of rain water being left behind on a windscreen to be wiped after each oscillatory movement of said oscillating arm. In the framework of the present invention the special ribs having a trapezium-shaped cross-section, extending in longitudinal direction of the wiper blade and protruding from said spoiler portion give the spoiler portion hydrophobic properties to drive rain and snow away, thereby avoiding said "after spray" phenomenon and thus improving the wiping qualities of the present windscreen wiper device .

It is noted that the present invention is not restricted to the use of only one longitudinal strip forming the elastic carrier that is particularly located in a central longitudinal groove of the wiper blade. Instead, said carrier may also comprise two longitudinal strips, wherein said strips are disposed in opposite longitudinal grooves of the wiper blade. Said groove(s) may be closed at one outer end.

Further, it is noted that in the invention use is made of a mounting head fixed for rotation to a 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 wiper 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.

Further, it is noted that said carrier is self-biased into a curved shape to bias said wiper strip into a curved configuration .

In a preferred embodiment of a windscreen wiper device in accordance with the present invention said carrier is self-biased into a curved shape to bias said wiper blade into a curved configuration.

The present invention also relates to a method of making a windscreen wiper device of the flat blade type, comprising the steps of - forming a longitudinally extending wiper blade of a flexible material including a wiping portion and a hinge portion integrally connected as one piece of said flexible material, and - forming a microtextured surface of said spoiler portion of said wiper blade, wherein said microtextured surface is provided with a plurality of ribs extending in longitudinal direction of the wiper blade and protruding from said spoiler portion , and wherein each rib has a cross-section in the form of a trapezium.

In a preferred embodiment of a method in accordance with the present invention the step of forming the wiper blade is further defined as extruding a longitudinally extending wiper blade of a flexible material. In the alternative the step of forming the wiper blade is further defined as injection or compression molding a longitudinally extending wiper blade of a flexible material.

In another preferred embodiment of a method according to the present invention the wiper blade is formed with a longitudinally extending groove and further including the step of inserting a carrier of a spring-like material into the groove to bias the wiper strip into a predetermined configuration .

In another preferred embodiment of a method in accordance with the present invention the microtextured surface is formed into a strip of starting material, wherein the strip is cut in at least two parts along a wiping edge which is intended to make contact with a windscreen to be wiped, and wherein said parts each form a wiper blade. As a result of the cutting operation, the strip of starting material is cut in two parts, one part forming the actual wiper blade with the microtextured surface, and the other part forming another wiper blade also with the microtextured surface. In other words, the strip of starting material comprises two wiper blades moulded together or extruded with their respective wiping edges being directed towards each other, wherein by cutting said strip along a wiping edge two separate wiper blades are provided.

In case the wiper blade is not made in one piece of said flexible material the invention also refers to a single spoiler portion, provided with said microtextured surface, wherein said spoiler portion is arranged to be detachably connected to said wiping portion of said wiper blade.

The invention will now be explained more in detail with reference to figures illustrated in a drawing, wherein - figure 1 is a perspective, schematic view of a preferred embodiment of a windscreen wiper device according to the invention; - figure 2 shows a perspective and a cross-sectional view, also in detail of a wiper blade, as used in a windscreen wiper device of figure 1; and - figure 3 is a cross-sectional view of the microtextured surface in a spoiler portion of the wiper blade of figure 2.

Figures 1 shows a preferred variant of a windscreen wiper device 1 according to the invention. Said windscreen wiper device 1 is built up of an elastomeric wiper blade 2 comprising a central longitudinal groove 3, wherein a longitudinal strip 4 made of spring band steel is fitted in said longitudinal groove 3. Said strip 4 forms a flexible carrier 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). The windscreen wiper device 1 is furthermore built up of a connecting device 5 of metal or plastic for connecting an oscillating wiper arm 8 thereto, with the interposition of a joint part 6. The oscillating wiper arm 8 is pivotally connected to the connecting device 5 about a pivot axis near one end. The preferred embodiment of figure 1 according to the invention comprises a spoiler or "air deflector" 7 which is made in one piece with the rubber wiper blade 2 and which extends along the entire length thereof. No end caps are used, but free ends of said wiper blade 2 are cut at an oblique angle.

Although not shown in figure 1, but fully understood by a skilled person, said oscillating arm 8 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 said oscillating arm 8 into rotation and by means of said connecting device 5 moves said wiper blade 2.

Said joint part 6 is detachably connected to said connecting device 5 by engaging protrusions 9 of said connecting device 5, at the location of said pivot axis, in co-axial recesses 10 provided in said joint part 6. As shown, said protrusions 9 extend outwards on either side of said connecting device 5.

The joint part 6 comprises a resilient tongue 11 extending outwardly, while the oscillating arm 8 has a U-shaped cross-section at the location of its connection to said joint part 6, so that the tongue 11 engages in an identically shaped hole provided in a base of said U-shaped cross-section. The connecting device 5 with the wiper blade 2 is mounted onto the oscillating arm 8 as follows. The joint part 6 being already clipped onto the connecting device 5 is pivoted relative to the connecting device 5, so that said joint part 6 can be easily slided on a free end of the oscillating arm 8. During this sliding movement the resilient tongue 11 is initially pushed in against a spring force and then allowed to spring back into said hole in said oscillating arm 8, thus snapping, that is clipping the resilient tongue 11 into the hole of the oscillating arm 8. This is a so-called bayonet-connection. The oscillating arm 8 together with the joint part 6 may then be pivoted back in a position parallel to the wiper blade 2 in order to be ready for use. By subsequently pushing in again said resilient tongue 11 against the spring force (as if it were a push button), the connecting device 5 and the joint part 6 together with the wiper blade 2 may be released from the oscillating arm 8. Dismounting the connecting device 5 with the wiper blade 2 from the oscillating arm 8 is thus realized by sliding the connecting device 5 and the joint part 6 together with the wiper blade 2 in a direction away from the oscillating arm 8.

In figure 2 on the right and in the middle said wiper blade 2 is drawn in perspective and in cross-section, wherein corresponding parts have been designated with the same reference numerals. Said wiper blade 2 comprises said spoiler 7 a wiping lip 12 having a triangular shape and a hinge 13, all made in one piece of material. Said spoiler 7 is provided along its entire length or along a portion of its length with a microtextured surface 14.

Figure 3 is a cross-sectional view of the microtextured surface 14 in the spoiler 7 of the wiper blade 2 of figure 2. Said microtextured surface 14 comprises ribs 15 extending in longitudinal direction of the wiper blade 2 and protruding from said spoiler 7. Said ribs 15 each have a cross-section in the shape of an iscosceles trapezium. A small base D of said trapezium has a length varying between 30 and 60 pm, while a large base E of said trapezium has a length varying between 70 and 120 pm. A protruding height C of said ribs varies between 60 and 80 pm, whereas the distance A between middle longitudinal planes 16 of adjacent ribs varies between 180 and 250 pm. A longitudinally extending free edge 17 of said wiping portion 12 does not contain said microtextured surface 14.

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

Claims

A flat blade type windshield wiper (1) comprising a longitudinally extending wiper blade (2) of a flexible material, the wiper blade (2) having a spoiler portion ( 7), a wiper part (12) and a hinge part (13) as one part integrally connected to the flexible material; at least one support (4) of a spring-like material, which effectively supports and biases the wiper blade (2) in a predetermined configuration; a connecting device (5) for connecting an oscillating arm thereto; wherein the spoiler part (7) of the wiper blade (2) is provided with a surface (14) with a micro-texture, characterized in that the surface (14) with the micro-texture comprises several ribs (15) extending longitudinally of the wiper blade (2) extend and protrude from the spoiler part (7), each rib (15) having a cross-section in the form of a trapezium.

A windscreen wiper (1) according to claim 1, wherein each rib (15) has a cross section in the form of an isosceles trapezium.

A windscreen wiper (1) according to claim 2, wherein a narrow base of the trapezium has a length between 30 and 60 µm, and wherein a broad base of the trapezium has a length between 70 and 120 µm.

A windscreen wiper (1) according to claim 2 or 3, wherein a projecting height of the ribs (15) lies between 60 and 80 µm.

A windscreen wiper (1) according to claim 2, 3 or 4, wherein the distance between center longitudinal planes of adjacent ribs (15) is between 180 and 250 µm.

A windscreen wiper (1) according to any one of the preceding claims 1 to 5, wherein a longitudinally extending free edge (17) of the wiper part (12) does not contain the surface (14) with the micro-texture.

A windscreen wiper (1) according to any one of the preceding claims 1 to 6, wherein the carrier (4) in a curved form is self-biased to bias the wiper blade (2) in a curved configuration.

A method for manufacturing a flat type windshield wiper (1) comprising the following steps of forming a longitudinally extending wiper blade (2) of a flexible material provided with a spoiler part (7), a wiper part (12) and a hinge part (13) integrally connected to the flexible material as one part; forming a surface (14) with a microstructure of the wiper blade (2) on the spoiler part (7), the micro-texture comprising several ribs (15) extending longitudinally of the wiper blade (2) and extending from the spoiler part (7) protruding, each rib (15) having a cross-section in the form of a trapezium.

A method according to claim 8, wherein the step of forming the erase sheet (2) is further defined as extruding a longitudinally extending erase sheet (2) of a flexible material.

A method according to claim 8, wherein the step of forming the wiper blade (2) is further defined as injection molding or compression molding of a longitudinally extending wiper blade (2) of a flexible material.

A method according to claim 8,9 or 10, wherein the wiper blade (2) is formed with a longitudinally extending groove (3) and further comprises the step of arranging a carrier (4) of a spring-like material in the groove (3) for biasing the erase sheet (2) in a predetermined configuration.

A method according to any one of the preceding claims 8 to 11, wherein the micro-texture surface (14) is formed from a strip of starting material, wherein the strip is cut into at least two parts (2) along an erasing edge (17) which is arranged to make contact with a window to be erased, and wherein each part (2) forms an erase sheet.