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Title:
A WINDSCREEN WIPER DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/160689
Kind Code:
A1
Abstract:
A windscreen wiper device (1) of the flat blade type, comprising a longitudinal strip (4), as well as an elongated wiper blade (2) of a flexible material (17), which can be placed in abutment with a windscreen to be wiped, which wiper blade is of the flat blade type and includes at least one groove (3), in which groove said longitudinal strip (4) is disposed, wherein said windscreen wiper device further comprises a connecting device (6) for detachably connecting said wiper blade (2) to an oscillating arm (17) said connecting device (6) having a substantially U-shaped cross-section, wherein legs of said U-shaped cross-section are connected to the flexible material (17) on opposite sides thereof, wherein said legs (14) are provided with two pairs of opposite protrusions (15), and wherein said protrusions (15) for exerting a transverse force on the flexible material, thereby locally squeezing said flexible material (17) onto said longitudinal strip (4).

Inventors:
BOLAND, Xavier (304 Route de Luxembourg, Arlon, Arlon, B-6700, BE)
Application Number:
EP2010/058908
Publication Date:
December 29, 2011
Filing Date:
June 23, 2010
Export Citation:
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Assignee:
FEDERAL-MOGUL S.A. (Avenue Champion, Aubange, B-6790, BE)
BOLAND, Xavier (304 Route de Luxembourg, Arlon, Arlon, B-6700, BE)
International Classes:
B60S1/38
Foreign References:
FR2854852A12004-11-19
EP2113432A12009-11-04
US20090307862A12009-12-17
US20070113366A12007-05-24
US20090056049A12009-03-05
DE102008041358A12010-02-25
Other References:
None
Attorney, Agent or Firm:
HOOIVELD, Arjen Jan Winfried (Sweelinckplein 1, GK Den Haag, NL-2517, NL)
Download PDF:
Claims:
CLAIMS

A windscreen wiper device (1), particularly for

automobiles, comprising an elastic, elongated carrier element, as well as an elongated wiper blade (2) of a flexible material (17), which can be placed in abutment with a windscreen to be wiped, which wiper blade (2) is of the flat blade type and includes at least one groove (3), in which groove (3) a longitudinal strip (4) of the carrier element is disposed, wherein said

windscreen wiper device (1) comprises a mounting head for transferring a reciprocal movement to an

oscillating arm (7), wherein said windscreen wiper device (1) further comprises a connecting device (6) for detachably connecting said wiper blade to said oscillating arm (7) near one end thereof around a pivot axis, characterized in that said connecting device (6) has a substantially U-shaped cross-section, wherein legs (14) of said U-shaped cross-section are connected to the flexible material (17) of said wiper blade on opposite sides thereof, wherein said legs (14) are provided with two pairs of opposite protrusions (15) near the outer ends of said connecting device (6), and wherein said protrusions (15) extend laterally inwardly for exerting only a transverse force on the flexible material (17) of said wiper blade (2), thereby locally squeezing said flexible material (17) onto said

longitudinal strip (4), in order to block any lateral movement of said longitudinal strip (4) at the location of the interconnection of said connecting device (6) and said wiper blade (2) . A windscreen wiper device (1) according to claim 1, wherein the ratio (1/ /L) between the width L' of said flexible material (17) at the location of said

protrusions (15) and the width L of said flexible material (17) at a location outside said protrusions (15) varies between 30% and 1 %.

A windscreen wiper device (1) according to claim 1 or 2, wherein said protrusions (15) have a round cross- section .

A windscreen wiper device (1) according to claim 1, 2 or 3, wherein said legs (14) of said U-shaped cross- section are movable from an open position, wherein said wiper blade (2) including said longitudinal strip (4) can be placed inside said connecting device (6) at the location of their interconnection, to a closed

position, and wherein said legs (14) are clamped around the flexible material (17) of said wiper blade.

A windscreen wiper device (1) according to claim 4, wherein said legs (14) of said U-shaped cross-section can be pushed against a spring force from the closed position into the open position, and wherein said legs (14) can be allowed to spring back from said open position into said closed position.

A windscreen wiper device (1) according to claim 4 or 5, wherein in said closed position said wiper blade (2) and said longitudinal strip (4) are mutually fixated by said legs (14) at the location of the interconnection of said connecting device (6) and said wiper blade (2), and wherein in said closed position said wiper blade (2) is allowed to move in longitudinal direction relative to said longitudinal strip (4) outside the location of the interconnection of said connecting device (6) and said wiper blade.

A windscreen wiper device (1) according to any of the preceding claims 1 through 6, wherein said connecting device (6) is detachably connected to said oscillating arm (7) with the interposition of a joint part (8), and wherein said joint part (8) is detachably connected to said connecting device (6) by engaging protrusions (10) of said connecting device (6), at the location of said pivot axis, in recesses provided in said joint part.

A windscreen wiper device (1) according to claim 7, wherein said joint part (8) has an at least

substantially U-shaped cross-section at the location of its connection to said connecting device (6), and wherein said joint part (8) is provided with said recesses (11) provided coaxially with said pivot axis.

A windscreen wiper device (1) according to claim 7 or 8, wherein the protrusions (10) extend outwards on either side of said connecting device (6) .

A windscreen wiper device (1) according to 7, 8 or 9, wherein said protrusions (10) are provided with co¬ axial through holes.

A windscreen wiper device (1) according to any of the preceding claims 7 through 10, wherein said joint part (8) comprises at least one resilient tongue (12) engaging in a correspondingly shaped hole (13) provided in a base of a U-shaped cross-section of said

oscillating arm (7), and wherein said resilient tongue (12) is rotatable along a hinge axis between an outward position retaining said wiper blade (2) onto said oscillating arm (7) and an inward position releasing said wiper blade (2) from said oscillating arm (7) .

A windscreen wiper device (1) according to any of the preceding claims 1 through 11, wherein said mounting head is fixed for rotation to a shaft, and wherein said shaft is rotatable alternately in a clockwise and in a counter-clockwise sense carrying said mounting head into rotation.

A windscreen wiper device (1) according to any of the preceding claims 1 through 12, wherein said windscreen wiper device (1) further comprises a connecting piece (5) positioned on both ends of said wiper blade (2) and connected to an end of said longitudinal strip (4) .

A wiper blade (2) of a flexible material (17), which can be placed in abutment with a windscreen to be wiped, which wiper blade (2) is of the flat blade type and includes at least one groove (3) in which groove

(3) a longitudinal strip (4) is disposed, said wiper blade (2) comprising a connecting device (6)

detachably connected thereto, characterized by said connecting device (6) having a substantially U-shaped cross-section, wherein legs (14) of said U-shaped cross-section are connected to the flexible material

(17) of said wiper blade on opposite sides thereof, wherein said legs (14) are provided with two pairs of opposite protrusions (15) near the outer ends of said connecting device (6), and wherein said protrusions (15) extend laterally inwardly for exerting only a transverse force on the flexible material (17) of said wiper blade (2), thereby locally squeezing said flexible material (17) onto said longitudinal strip

(4), in order to block any lateral movement of said longitudinal strip (4) at the location of the

interconnection of said connecting device (6) and said wiper blade (2 ) .

Description:
A WINDSCREEN WIPER DEVICE

The present invention relates to a windscreen wiper device, particularly for automobiles, 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 is of the flat blade type and includes at least one groove, in which groove a longitudinal strip of the carrier element is disposed, wherein said windscreen wiper device comprises a mounting head for transferring a reciprocal movement to an oscillating arm, wherein said windscreen wiper device further comprises a connecting device for detachably

connecting said wiper blade to said oscillating arm near one end thereof around a pivot axis.

The invention also refers to a wiper blade to be used in such a windscreen wiper device. Such a windscreen wiper device and such a wiper blade are generally known. This prior art wiper blade 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 element, as a result of which it exhibits a specific

curvature. In practice said wiper blade often comprises a spoiler at a side thereof facing away from the windscreen to be wiped. The spoiler is also called an "air deflector". The object of the invention is to provide an improved windscreen wiper device. 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 connecting device has a substantially U-shaped cross- section, wherein legs of said U-shaped cross-section are connected to the flexible material of said wiper blade on opposite sides thereof, wherein said legs are provided with two pairs of opposite protrusions near the outer ends of said connecting device, and wherein said protrusions extend laterally inwardly for exerting only a transverse force on the flexible material of said wiper blade, thereby locally squeezing said flexible material onto said longitudinal strip, in order to block any lateral movement of said longitudinal strip at the location of the interconnection of said connecting device and said wiper blade. In use, during each oscillatory movement of said oscillatory arm, said wiper blade at the location outside said connection device would normally suffer from the so-called "fishtailing phenomenon", wherein said wiper blade on opposite sides of said connecting device vibrates in an uncontrollable manner parallel to a windscreen to be wiped. Obviously, this

"fishtailing phenomenon" results in deteriorated wiping properties, with all negative consequences involved, particularly at high speeds. According to the invention said protrusions extend laterally inwardly only from a vertical part of each leg of said U-shaped cross-section for exerting only a transverse force on the flexible material of said wiper blade, thereby allowing said longitudinal strip to exhibit a curvature at the location of the interconnection of said connecting device and said wiper blade. Experimental results have shown that the "fishtailing phenomenon" is avoided at least to a large extend, so that the wiping properties are improved. Preferably, the ratio (1 /L) between the width L' of said flexible material at the location of said protrusions and the width L of said

flexible material at a location outside said protrusions (but inside said connecting device) varies between 30% and 1 %. Preferably, said protrusions have a round cross-section.

It is noted that the present invention is not restricted to the use of only one longitudinal strip forming the elastic carrier element that is particularly located in a central longitudinal groove of the wiper blade. Instead, said carrier element may also comprise two longitudinal strips, wherein said strips are disposed in opposite longitudinal grooves of the wiper blade. Further, the present invention is not restricted to automobiles, but also refers to other fast vehicles, such as trains and the like.

In a preferred embodiment of a windscreen wiper device in accordance with the invention said legs of said U-shaped cross-section are movable from an open position, wherein said wiper blade including said longitudinal strip can be placed inside said connecting device at the location of their interconnection, to a closed position, and wherein said legs are clamped around the flexible material of said wiper blade. With the use of a special tool, said legs are particularly pushed against a spring force (as a result of the elasticity of the material from which the connecting device is made) from the closed position into the open position, wherein said legs are allowed to automatically spring back from said open position into said closed

position.

In another preferred embodiment of a windscreen wiper device according to the invention in said closed position said wiper blade and said longitudinal strip are mutually fixated by said legs at the location of the interconnection of said connecting device and said wiper blade, wherein in said closed position said wiper blade is allowed to move in longitudinal direction relative to said longitudinal strip outside the location of the interconnection of said

connecting device and said wiper blade. In other words, the wiper blade and the longitudinal strip are not allowed to mutually move under the connecting device, but in all other areas along the wiper blade a slight movement thereof is made possible in order to allow said wiper blade to follow any curvature of the windscreen to be wiped. In said closed position said legs are particularly slightly deforming (the rubber of) said wiper blade at the location of the

interconnection of said connecting device and said wiper blade .

In another preferred embodiment of a windscreen wiper device in accordance with the invention said connecting device is detachably connected to oscillating arm 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. This is preferably realized through a snapping or clipping operation .

In another preferred embodiment of a windscreen wiper device according to the invention said joint part has an at least substantially U-shaped cross-section at the location of its connection to said connecting device, wherein said joint part is provided with said recesses provided coaxially with said pivot axis. In particular, the protrusions extend outwards on either side of said connecting device and are preferably cylindrical in shape. In the alternative, said protrusions are spherical or frusto-conical in shape. Said protrusions that function as bearing surfaces are thus paced far apart, so that forces exerted thereon will be relatively low. In yet another preferred variant said joint part is provided with co-axial through holes in legs of said U- shaped cross-section thereof, wherein a pivot pin is

inserted in said through holes. Accordingly, the wiper blade may then be connected to the oscillating arm on the basis of a so-called "sidelock system". The oscillating arm is provided with a joint pin or a pivot pin to be inserted in said co-axial through holes. Said pivot pin protrudes in a direction towards the wiper blade and has a pivot axis extending in a direction of the oscillating movement of the oscillating arm.

In another preferred embodiment of a windscreen wiper device in accordance with the invention said joint part comprises at least one resilient tongue engaging in a correspondingly shaped hole provided in a base of a U-shaped cross-section of said oscillating arm, and wherein said resilient tongue is rotatable along a hinge axis between an outward position retaining said wiper blade onto said oscillating arm and an inward position releasing said wiper blade from said

oscillating arm. Accordingly, the wiper blade may then be connected to the oscillating arm on the basis of a so-called "toplock system" on the basis of a bayonet connection. In order to connect the wiper blade onto the oscillating arm , the resilient tongue is initially pushed in against a spring force - as if it were a push button - and then allowed to spring back into the hole provided in the oscillating arm, thus snapping, that is clipping the resilient tongue into the hole. By subsequently pushing in again the resilient tongue against the spring force, the wiper blade may be released from the oscillating arm. A windscreen wiper device according to the invention

comprises 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. Said oscillating arm is connected to said mounting head fixed for rotation to said 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 into rotation and by means of said

connecting device moves said wiper blade. Further, a

windscreen wiper device in accordance with the invention comprises a connecting piece positioned on both ends of said wiper blade and connected to an end of said longitudinal strip .

The present invention also relates to a wiper blade

manufactured as a single (separate) constructional element of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade is of the flat blade type and includes at least one groove in which groove a longitudinal strip is disposed, said wiper blade

comprising a connecting device detachably connected thereto, characterized by said connecting device having a

substantially U-shaped cross-section, wherein legs of said U-shaped cross-section are connected to the flexible

material of said wiper blade on opposite sides thereof, wherein said legs are provided with two pairs of opposite protrusions near the outer ends of said connecting device, and wherein said protrusions extend laterally inwardly for exerting only a transverse force on the flexible material of said wiper blade, thereby locally squeezing said flexible material onto said longitudinal strip, in order to block any lateral movement of said longitudinal strip at the location of the interconnection of said connecting device and said wiper blade.

It is noted that the connecting device is not necessarily made in one piece, but it can also be composed of an

assembly of parts.

The invention will now be explained more in detail with reference to figures illustrated in a drawing, wherein figures 1A and IB are a perspective, schematic view of a preferred embodiment of a windscreen wiper device according to the invention, with and without (a part of) an oscillating arm, respectively, whereas figure 1C is a cross-sectional view of figure 1A at the location of a connecting device;

figure 2 is a top view of a longitudinal section of a wiper blade used in the windscreen wiper device of figure 1, at the location of the interconnection between the wiper blade and a connecting device for the oscillating arm;

figure 3 is perspective view of a cross-section of the connecting device of figure 2; and

figure 4 schematically shows the so-called "fishtailing phenomenon".

Figure 1 shows a preferred variant of a windscreen wiper device 1 according to the invention. Said windscreen wiper device is built up of an elastomeric (rubber) 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 (see figures 5, 6 and 7) . Said strip 4 forms 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) . An end of said strip 4 and/or an end of said wiper blade 2 is connected on either side of the windscreen wiper device 1 to respective connecting pieces or "end caps" 5. In this embodiment, the connecting pieces 5 are separate constructional elements, which may be form- locked as well as force-locked to both ends of said strip 4 and/or ends of said wiper blade 2. In another preferred variant, said connecting pieces 5 are in one piece with the strip 4 made of spring band steel. The windscreen wiper device 1 is furthermore built up of a connecting device 6 of metal for connecting an oscillating wiper arm 7 thereto, with the interposition of a joint part 8. The oscillating wiper arm 7 is pivotally connected to the connecting device 6 about a pivot axis near one end. The preferred embodiment of figure 1 according to the invention comprises a spoiler or "air deflector" 9 which is made in one piece with the rubber wiper blade 2 and which extends along the entire length thereof.

Although not shown in figure 1, but fully understood by a skilled person, said oscillating arm 7 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 7 into rotation and by means of said

connecting device 6 moves said wiper blade 2.

As shown in figure 1, the connecting device 6 comprises two cylindrical protrusions 10 extending outwards on either side of said connecting device 6. These protrusions 10 pivotally engage in identically shaped cylindrical recesses 11 of the plastic joint part 8. Said protrusions 10 act as bearing surfaces at the location of the pivot axis in order to pivot the joint part 8 (and the oscillating arm 7 attached thereto) about the pivot axis near one end of the

oscillating arm 7. The protrusions 10 are preferably in one piece with said connecting device 6. In the alternative, said protrusions 10 are part of a single pivot pin

perpendicular to the connecting device 6. As can be seen in figure 1, the joint part 8 comprises a resilient tongue 12 extending outwardly, while the oscillating arm 7 has an U- shaped cross-section at the location of its connection to said joint part 8, so that the tongue 12 engages in an identically shaped hole 13 provided in a base of said U- shaped cross-section. The connecting device 6 with the wiper blade 2 is mounted onto the oscillating arm 7 as follows. The joint part 8 being already clipped onto the connecting device 6 is pivoted relative to the connecting device 6, so that said joint part 8 can be easily slided on a free end of the oscillating arm 7. During this sliding movement the resilient tongue 12 is initially pushed in against a spring force and then allowed to spring back into said hole 13, thus snapping, that is clipping the resilient tongue 12 into the hole 13. This is a so-called bayonet-connection. The oscillating arm 7 together with the joint part 8 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 12 against the spring force (as if it were a push button), the connecting device 6 and the joint part 8 together with the wiper blade 2 may be released from the oscillating arm 7. Dismounting the connecting device 6 with the wiper blade 2 from the oscillating arm 7 is thus realized by sliding the connecting device 6 and the joint part 8 together with the wiper blade 2 in a direction away from the oscillating arm 7. Figures 2 and 3 show a top view of a longitudinal section and a perspective view of a cross-section of the connecting device 6, showing the working principle of the connecting device 6 according to the invention As mentioned earlier and with reference to figure 3, this connecting device 6 has a U-shaped cross-section with legs 14 having a C-shaped cross- section. With the help of a special tool (not shown) said legs 14 are moved from a non-operative position into an operative position. In fact, said tool pushes said legs 14 outwardly against a spring force of the metal from which the connecting device 6 is manufactured. This is possible as a result of the elastical properties of the metal. In said open position said wiper blade 2 is mounted inside said connecting device 6 at the location of their

interconnection, to an intermediate position. In the latter position the longitudinal strip 4 of the carrier element is slided into the central longitudinal groove 3 of the wiper blade 2. If considered expedient, a lubricant is used to facilitate insertion of the longitudinal strip 4 inside said longitudinal groove 3. Finally, when the wiper blade 2 and the longitudinal strip 4 are in the right position, the special tool is removed. Consequently, said legs 14 of said connecting device 6 are allowed to spring back into a closed position, wherein said legs 14 are clamped around said wiper blade 2, while slightly deforming the rubber of said wiper blade 2 at the location where the legs 14 engage the rubber. In said closed position said wiper blade 2 and said

longitudinal strip (4) 4 are mutually fixated by said legs 14 at the location of the interconnection of said connecting device 6 and said wiper blade 2, whereas in said closed position said wiper blade 2 is allowed to move in

longitudinal direction relative to said longitudinal strip 4 outside the location of the interconnection of said

connecting device 6 and said wiper blade 2.

Now referring to figure 2 said legs 14 are provided with two pairs of opposite protrusions 15 near the outer ends 16 of said connecting device 6, wherein said protrusions 15 extend laterally inwardly for exerting only a transverse force on the rubber 17 of said wiper blade 2, thereby locally

squeezing said rubber 17 onto said longitudinal strip 4. Accordingly, any lateral movement of said longitudinal strip 4 at the location of the interconnection of said connecting device 6 and said wiper blade 2 is blocked. The protrusions 15 have the following additional function. In use, during each oscillatory movement of said oscillatory arm 7, said wiper blade 2 at the location outside said connection device 6 would normally suffer from the so-called "fishtailing phenomenon", wherein said wiper blade 2 on opposite sides of said connecting device 6 vibrates in an uncontrollable manner parallel to a windscreen to be wiped. Obviously, this "fishtailing phenomenon" results in deteriorated wiping properties, with all negative consequences involved,

particularly at high speeds. According to the invention said protrusions 15 extend laterally inwardly only from a

vertical part 18 of each leg 14 of said U-shaped cross- section for exerting only a transverse force on the rubber 17 of said wiper blade 2. Hence, said longitudinal strip 4 is allowed to exhibit a curvature at the location of the interconnection of said connecting device 6 and said wiper blade 2 (see figure 3) . Experimental results have shown that the "fishtailing phenomenon" is avoided at least to a large extend, so that the wiping properties are improved.

Preferably, the ratio (1/ /L) between the width L' of said rubber 17 at the location of said protrusions 15 and the width L of said rubber 17 at the location outside said protrusions 15 varies between 30% and 1 % (see figure 2) . As shown, said protrusions 15 have a round cross-section.

In figure 4 are shown longitudinal sections of a wiper blade 2 at the location of the connecting device 6 according to the invention (left) and according to the prior art. As can be seen, the protrusions 15 exert only a transverse force onto the rubber 17, thereby avoiding the so-called

"fishtailing phenomenon". According to the prior art the wiper blade 2 on opposite sides of the connecting device 6 vibrates in an uncontrollable manner parallel to a

windscreen to be wiped.

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.