The present invention relates to a windscreen wiper assembly for clearing the surface of a windscreen of, for example, water, ice, dirt, insects, grease and the like. By the term "windscreen" it is intended to include not only a front screen of a vehicle but also, for example, a rear screen and a headlamp screen, or lens of the vehicle.

SUBSTITUTE SHEET

It has long been known to clear the outer surface of vehicle windscreens with a reciprocating wiper comprising a flexible blade which is drawn over the surface in a reciprocating manner at an acute angle to the surface. Such blades are highly efficient at removing water from the screen but it has been found that they have a tendency to smudge or smear other matter adhering to the surface.

In order to overcome this problem, it has been proposed to provide separate brush means to remove matter other than water from the screen. In Australian published speci ication 53423/79, a wiper blade is provided together with a brush attached to jacking means. Normally the jacking means is retracted so that the wiper blade operates in usual manner but if there is debris on the screen the jacking means may be extended whereby the brush engages the screen. Such engagement of the brush causes the wiper blade to lift from the screen so that it is possible to only have either the blade or the brush operating at any one time. This arrangement is disadvantaged by being manually operable and requiring relatively expensive apparatus.

In Australian patent specification 287460, it is proposed to provide a wiper blade with scraper means in the form of bristles projecting forwardly and rearwardly from the lateral sides of the blade. The arrangement is such that when the blade pivots in known manner about its length to begin the sweep the forwardly directed bristles are automatically brought into engagement with the screen, while the rearwardly directed bristles are lifted off the screen. As the wiper sweeps across the screen, the leading bristles engage any debris on the screen before the wiper blade. However, the bristle are rigidly secured to the blade in such a manner that when the tips of the bristles engage debris on the

screen the increased resistance to movement of the bristles across the screen will likely cause a reaction force to be transferred to the blade and thereby tilt the blade out of its optimum operating angle so that the blade may no longer operate satisfactorily to remove water from the screen. Furthermore, in order to operate satisfactorily, the blade must be relatively flexible and the rigid attachment of the bristles to the blade has a tendency to reduce such flexibility, at least when the bristles are in engagement with the screen.

It is an object of the present invention to alleviate the aforementioned disadvantages of the prior proposed windscreen wipers and there is accordingly provided a windscreen wiper assembly adapted to clean a windscreen by reciprocating motion across the surface of the windscreen, comprising:- blade means comprising an elongate flexible wiping blade engageable with the surface and pivotable about an axis parallel to its length to orientate the blade relative to the -surface according to the direction of movement of the blade means across the surface to thereby wipe said surface in at least one direction of movement, and an elongate scrubber adapted to engage the surface and scrape deposited material from the surface, the scrubber being located at the leading lateral side of the blade in said one direction of movement and arranged such that when leading and when trailing behind the blade means in the respective directions of movement of the blade means across the surface the scrubber is respectively in and out of engagement with the surface, the scrubber when leading the blade means being pivotable independently of the blade.

By the present invention, the blade is tiltable about its length to an optimum working angle, which is usually acute relative to the direction of movement of the blade means across the screen and a scrubber is automatically brought into engagement with the screen when it is on the leading side of the blade means and is displaceable independently of the blade. Thus, when the scrubber is in engagement with the screen and it strikes debris on the screen ahead of the blade the scrubber can be displaced relative to the blade due to the increased drag without effecting to any great extent the wiping effect of the blade. Such displacement of the scrubber relative to the blade is preferably by independent pivotal movement, but may also, or alternatively, be by distortion or flexing of the scrubber itself. Pressure applied through the wiper blade from a spring loaded wiper arm onto the screen is less severely affected by the arrangement of the present invention than by other known proposals. The blade means may comprise two elongate flexible wiping blades in side by side array and pivotable about respective axes parallel to their lengths in order to permit orientation relative to the surface of the trailing blade in the respective sense of direction of movement of the blade means across the surface whereby the trailing blade is adapted to wipe the surface, in which case the scrubber, when leading the blade means, must be pivotable independently of the said trailing blade. Thus, in this arrangement the trailing blade will perform the usual wiping function and preferably the wiper assembly is such that the leading blade in the respective sense of direction of movement of the blade means across the surface is pivoted out of engagement with the surface.

As heretofore described, the windscreen wiper assembly in accordance with the present invention only has a scrubber available to scrape debris from the screen in one sense of direction of movement of the wiper assembly across the screen. Advantageously such scraping may be performed in both senses of direction of movement of the wiper and there are accordingly preferably provided two elongate scrubbers each adapted to engage the surface and scrape deposited material from the surface, the scrubbers being located at respective lateral sides of the blade means and arranged such that the leading and trailing scrubbers in the respective sense of direction of movement of the blade means across the surface are respectively in and out of engagement with the surface, the leading scrubber being displaceable independently of the blade or of the aforementioned trailing blade.

Where only one blade is provided, the scrubber or scrubbers must be displaceably, preferably pivotally, supported independently of the blade, although tilting movement of the blade may also affect the scrubber or scrubbers, for example to move the scrubber or scrubbers into or out of engagement with the surface. Where two wiper blades are provided, the scrubber or scrubbers may again be displaceably supported independently of the wiper blades, but preferably the or each scrubber is carried by a respective blade. By this latter arrangement, a scrubber carried by the leading wiper blade may pivot into engagement with the surface, and at the same time lift the leading blade out of engagement with the surface, without substantially affecting the operational angle of the trailing blade. With the trailing blade in engagement with the surface, a trailing scrubber is automatically pivoted out of engagement. Advantageously the or each scrubber is separable from the

wiper and may be replaced if it becomes worn. Since the or each scrubber is adapted to remove any debris on the surface, the operational life of the wiper blade should be extended. The or each scrubber may take any one of a variety of forms. For example, a scrubber may be in the form of a brush having bristles projecting generally forwardly on the leading side of the wiper. However, a brush is not preferred since the bristles have a tendency to distort when engaging debris on the screen and are not self-cleaning. The bristles could be provided on one or both of two wiper blades or be supported for separate pivotal movement relative to the or each wiper blade. Preferably the or each scrubber is such that the independent displacement of the scrubber in engagement with the screen surface permits said scrubber to engage with the surface to a greater or lesser extent with, respectively, increased or decreased frictional resistance between said scrubber and the surface without substantially affecting the wiping action of the blade or of the trailing blade. Thus, when the scrubber which leads the blade means across the surface engages only water on the surface, it_ may be in only light engagement with the surface thereby minimising frictional resistance and wear of the scrubber. However, when the scrubber strikes debris on the surface, the frictional resistance will increase thereby holding back the scrubber and such holding back may increase the force with which the scrubber engages the surface and the debris thereon. The or each scrubber may comprise a spongy body which may distort under resistance to movement across the surface under pressure with the screen, and also absorb water from the surface for future use. Such a body may be in the form of a nylon honeycomb webbing of sponge- like material with a coarse surface. Alternatively the

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scrubber may comprise a substantially rigid body. The surface of the scrubber, whether the body thereof is soft or rigid, preferably defines at least two working surfaces of the scrubber assembly so that under normal conditions when only water is being swept from the screen a first low friction surface portion engages the screen under low contact pressure, whereas under scrubbing conditions produced by increased resistance to movement, a second scrubbing portion may be engaged. The second scrubbing portion may be engaged merely by pivotal movement of the scrubber or also, or alternatively, by deformation or distortion of the aforementioned sponge¬ like body. The second scrubbing portion of the body may be provided with a coarser or more rigid surface structure, such as projections from the surface, and/or the surface structure may have a greater length. Under neutral conditions the body may be circular, generally diamond shaped with the first scrubbing portion defined on one face and the second scrubbing portion on another face which is brought into engagement with the screen by increased pivotal movement of the scrubber, or any other suitable shape which in use defines two distinct working portions of the scrubber assembly.

In order to perform the above two-stage scrubbing, the scrubber or scrubbers may alternatively be substantially freely pivotable under low friction conditions but be restricted in the pivotal movement under high friction conditions. Thus, when the working scrubber pivots beyond a predetermined condition it may come into engagement .with a backing member, for example, which limits the movement so that a greater force is applied to the surface through the scrubber. Where the or each scrubber is carried by a respective blade, the backing member may be engaged by the blade body to limit pivotal movement of the leading scrubber, and likewise

the blade body of the trailing blade may engage the backing member to limit pivotal movement of the trailing blade, such engagement possibly being through the trailing scrubber. The blade body, the scrubber and/or the backing member may all be suitably shaped to provide such engagement and should also be shaped such that the leading blade and/or scrubber do not materially affect the working function of the trailing blade.

Preferably the or each blade is supported by a reduced thickness neck portion to provide the pivotal movement of the blade (and if provided, of the associated scrubber) and the leading blade is displaceable into a space defined adjacent said neck portion of the trailing blade. The leading blade tip may, in use, engage the trailing blade to close said space but particularly where the pivotal movement of the trailing blade is limited by, for example, the trailing scrubber, such engagement need not affect the working function of the trailing blade. Where the or each scrubber is carried by a respective wiper blade, the scrubber may be formed integrally with the blade and of the same material, for example rubber. The scrubber may be cam shaped to define two working portions and_ may comprise a soft body but preferably it has a substantially rigid structure. According to a preferred embodiment however, each scrubber comprises a rigid body having elongate blade¬ like projections which are angled such that under normal conditions as each blade-like projection engages the screen with greater or lesser pivotal movement of the scrubber assembly it lies at an angle of 15-45 degrees to the screen, and preferably between 25 and 35 degrees, to provide a razor-like scraping action. The blade-like projections may be formed on a removable insert, formed of, for example, nylon or acetal. Alternatively a separately-formed scrubber may be attached to the blade

means by moulding or by adhesive. It will be appreciated that the lower the angle of contact of each projection with the screen, the lower the accompanying scraping noise will be. Advantageously the wiper assembly also includes a wing or flair integrally moulded therewith which is such that airflow over the windscreen caused by forward motion of the vehicle will flow over the wing or flair in a manner which forces the wing or flair and therefore the wiper onto the screen. Preferably such wing or flair extends the full length of the wiper blade means, as does the or each scrubber.

Various embodiments of a wiper assembly in accordance with the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figures 1 to 14 illustrate in cross-section a plurality of embodiments of a wiper assembly in accordance with the invention, together with modifications thereto, in which each scrubber is separately pivotably mounted relative to a wiper blade, and

Figures 15 to 24 illustrate in cross-section a plurality of embodiments of a wiper in accordance with the invention, together with modifications thereto, in which each scrubber is mounted on a respective one of two wiper blades.

In the following description, for convenience, the same or similar parts in different embodiments will be given the same reference numeral.

The following description relates to windscreen wiper assemblies such as may be used in vehicles and which are held against the windscreen by means of a spring-loaded arm connected to a motor to provide reciprocating motion to the arm and wiper assembly across

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the screen. The wiper assembly is held in well known manner by means of a slide member attached to the wiper and a claw attached to the arm. The slide and claw are such as to prevent or at least severely limit pivotal movement therebetween, any such pivotal movement being as a result of the necessity to permit the slide and claw to be released from each other. In the embodiments of the invention illustrated, the slide is not always shown but it will be appreciated that the slide or similar means to connect the wiper assembly to the arm will always be provided.

Referring now to Figure 1, there is shown a windscreen wiper assembly comprising an elongate blade 1 of triangular cross-section and having a screen engaging tip 2, the blade being integrally moulded in rubber with a flexible neck 3. The neck 3 has a cross piece 4 also integrally formed in rubber but relatively rigid compared to the neck. If the cross piece 4 is insufficiently rigid, a co-operating rigid plate (not shown) may be associated with it. Extending from above the cross piece 4 is an integral rubber slide member 5 which is adapted to be received in a claw of a spring-loaded wiper arm. In use, the claw of the wiper arm will extend around the slide member 5 and abut the top surface of the cross piece 4 whereby the cross piece is held substantially rigid relative to the wiper arm Also integrally formed with the neck 3 and extending therefrom between the cross piece 4 and the blade 1 is a support member 6 having a pair of depending slide jaws 7 at its lateral extremities. The support member 6 may be relatively flexible compared to the cross piece 4 and if so, as shown, may be supported by a rigid member 8, for example of steel. The rigid member 8 may be introduced during moulding of the wiper assembly, but as shown, is introduced subsequently and is formed in two

parts on respective sides of the neck 3, the neck 3 having a longitudinal array of slots therein through which interlocking portions of the member 8 pass. The rigid member 8 has two series of openings therein through which inter-engaging pegs 9 formed integrally with the support member 6 are located. By this arrangement, the support member 6 is made rigid with the member 8.

Two scrubbers 10 are suspended for pivotal movement from respective slide jaws 7 and independently of the blade 1, each scrubber comprising an elongate body 11 of generally diamond shaped cross section with a flattened top 12 and a flexible neck 13 extending therefrom. At its distal end, each neck 13 has an elongate bead 14 which is received in sliding manner by the slide jaw 7 to provide an interference fit therebetween. Each scrubber body 11 may comprise a relatively soft, flexible material, for example a honeycomb sponge material of nylon which may absorb water and which will function substantially as shown in Figure 5b or a relatively rigid material, such as rubber or a suitable plastics, which will function substantially as shown in Figure 6b. The surface of the body 11 has a short bristle-like or webbed formation whereby the projections defined thereby may engage the surface of the screen 15 to scrape debris from the screen.

In operation of the wiper, for example when moving to the right in the drawing, the blade 1 tilts relative to the slide member 5 and cross piece 4 through flexing of the neck 3. Such flexing or pivotal movement causes the right-hand end of the support member 6 and rigid member 8 to dip and the left-hand end to raise. The angle of inclination of the blade 1 and the corresponding tilting of the assembly of members 6 and 8 is such that the left-hand scrubber is raised off the surface of the screen and the right-hand slide jaw 7 is

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moved closer to the screen. The maximum pivotal movement of the assembly of the members 6 and 8 is limited by the engagement of the left-hand end of the rigid member 8 with the cross piece 4, but the blade 1 may pivot relative to the members 6 and 8 through the flexibility of the portion of the neck 3 below the support member 6. Under normal wiping conditions, the upper left-hand corner of the blade engages the support member 6 to tilt the assembly of members 6 and 8. Lowering of the right- hand slide jaw 7 permits the right-hand scrubber 10 to trail behind its slide jaw 7, whereby when the screen 15 is merely wet, a first surface portion 16 of the body 11 engages the screen with minimum friction therebetween since some lift is provided by the neck 13. When the right-hand scrubber 10 strikes debris on the screen, friction between the screen and the scrubber increases causing the scrubber to be held back thereby pivoting the assembly of members 6 and 8 to their maximum extent and causing the second surface portion 17 of the scrubber to come into engagement with the screen, either by flexing of the body 11 or merely by pivoting movement of the scrubber about neck 13. The second surface portion 17 is adapted to provide a greater scrubbing effect than the first surface portion 16, for example by having sharper or more rigid surface projections and by there being a greater force therethrough onto the screen to remove the debris. The added pressure applied to the scrubber is caused by the adjustment in the direction of downward pressure when the assembly of members 6 and 8 tilts further on engagement by the scrubber with the debris. Furthermore, with the lowering of the right-hand jaw 7, there will be minimal lifting force applied to the right-hand scrubber. Removal of the debris may of course take more than one sweep of the wiper.

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The positioning of the blade 1 and scrubbers 10 is be such that the working scrubber, even when deformed, still permits the blade to pivot independently and the embodiment illustrated in Figure 1 alleviates the problems of lifting of the blade tip during heavy scrubbing, rigidity of the blade and generally loss of wiper arm pressure to the blade. At the end of the sweep of the wiper to the right in the drawing, when the wiper arm begins to move to the left, the blade 1 will pivot about the neck 3 whereby the right-hand end of the assembly of members 6 and 8 is raised and the left-hand end is dropped.

The flexibility, if any, of each scrubber 10 and the pivotal movement in the neck 13 must be taken into account in determining the displacement of the scrubber through the pivotal movement of the assembly of members 6 and 8, in order to ensure minimal interference with the operation of the blade 1 and optimum operation of the scrubber in both its working conditions. It will be appreciated that only one scrubber need be provided but scrubbing action will then only be provided in the one sense of direction. As shown, the scrubbers have surface projections on both sides thereof so that they may be rotated through 180 degrees if the projections on one side become worn or distorted, to utilise the other side. Alternatively, the two scrubbers may be swapped with each other so that the other side of each is used.

In Figure 2, the assembly of flexible rubber support member 6 and rigid member 8 of Figure 1 have been replaced by a thicker integral rubber support 18 which is able to support itself from the neck 3. The support 18 is relatively rigid and the majority of the pivotal movement occurs in the portions of the neck 3 above and below the support. The support is tapered to either side

of the neck 3 to enable the desired amount of pivotal movement about the neck to take place before the support abuts the cross piece 4. The blade 1 may pivot independently of the scrubbers 10 and of the support 18 through the portion of the neck 3 between the blade and the support. The operation of the wiper assembly of Figure 2 is otherwise identical to that of Figure 1.

The wiper illustrated in Figure 3 is similar to that shown in Figure 2 in that the independent scrubbers 10 are supported by an integral rubber support 18' which is self-supporting from the neck 3. The support 18' is not tapered on its upper surface but pivotal movement thereof occurs through the neck 3 whereby the upper surface can abut the cross piece 4. The shape of the blade 1' is different to that of the previous two embodiments in that it has rounded cut out portions 19 to give the blade 1' flexibility relative to the support 18' . The scrubbers 10 are independently pivoted in the same manner as in the embodiment of Figure 2, and as shown in Figure 3 when the wiper is moved to the left the support 18' pivots about the neck 3 so that the blade 1' lies at an acute angle relative to the portion of the screen to be wiped. The right-hand scrubber 10 is accordingly raised from the screen while the left-hand scrubber 10 is lowered onto the screen. The shape of the body of the left-hand scrubber 10 is shown under normal conditions when the screen is merely wet so that only a first portion of the surface of the body is in engagement with the screen. It will be seen that the scrubber 10 fits partly into the cut out neck portion 19 of the blade permitting the independent movement of the scrubber and of the blade. When the left-hand scrubber strikes debris on the screen, the scrubber will be restrained from forward movement so that the second working surface portion of the body 11 is brought into engagement by

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flexing of the body, by further pivotable movement in the neck member 13 and in the neck 3, and possibly by some flexing of the support 18', all of which combine to produce a greater interaction between the second working surface of the scrubber and the screen. When the left- hand scrubber moves into its second working condition, the left-hand cut out portion 19 will close slightly as the blade tip remains at the same acute angle to the screen 15. Referring now to Figure 4, a further modification to the wiper assembly shown in Figure 1 is illustrated, with the blade 1, lower, neck portion 3 and support member 6 in Figure 1 being replaced by an integral molding similar to that shown in Figure 3. Thus, a solid rubber support 18' ' extends from the neck 3 and is itself supported by a rigid member 8 although this may be dispensed with if the support is sufficiently rigid itself. The support is formed integrally with slide jaws 7 to receive scrubbers 10 as in the previously described embodiments. The support 18 ' ' tapers into a recessed neck portion 19' from which extends the integrally formed blade I' *. Limited flexing of the blade I* ' is permitted through the neck portion 19' and, as in the Figure 3 embodiment, the recessed portion 19' opens up when the support member 18' * and blade I ¹ ' are tipped over in operation to permit the leading scrubber 10 to sit partly in the recessed portion. The majority of the flexing of the blade in this embodiment is through the neck 3 above the support member 18 ^* * and in the blade tip, but the scrubbers 10 are independently pivoted relative to the blade through the flexible neck members 13.

Referring now to Figures 5a and 5b, a further modification to the type of wiper in accordance with the invention shown in Figure 1 is illustrated, in this

instance the difference from the Figure 4 embodiment being only in the shape of the blade l' ^{* *} and support 18- ^{* 1} . Thus, the blade has a slightly greater taper than the blade I' ¹ of Figure 4 and is joined across its full cross-sectional width with the support 18 ' * ' , so that no recessed portion is provided between the two. As shown in Figure 5b, the scrubbers 10 are sufficiently spaced from the blade 1' ' ' to not abut the blade in use, the scrubbers being of a flexible nature. Also as shown in Figure 5b, the rubber blade I'-' has a degree of flexibility but the majority of the pivoting thereof is performed through the neck 3, with the scrubbers 10 again being independently pivotable relative thereto.

As in all the aforementioned embodiments, the loss of wiper height from the neutral condition shown in Figure 5a to the working condition shown in Figure 5b due to tilting movement of the blade must not be greater than the lifting effect to the trailing scrubber 10 caused by the pivotal movement of the support 18 * * * , or the trailing scrubber will not be lifted from the screen surface. It is important that the trailing scrubber 10 is lifted from the surface since it will otherwise have a tendency to leave a blur across the screen. The controlled loss of height of the wiper and the lift to the trailing scrubber must be built into the design of the wiper. The loss of height of the wiper due to pivotal movement of the blade must also be sufficient to permit the blade tip 2 to work freely, that is to bend flexibly under pressure over the screen 15. It may be noted that the blade will require less pressure than a wiper assembly in which only a blade is provided to perform its function satisfactorily and the pressure from the wiper arm may be equally shared between the blade and leading scrubber 10 or even scrubber biased. The controlling influence of the leading scrubber over the

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blade should be minimal and, where there is any such influence, it may be used to maintain a preferred blade angle.

Figure 5b illustrates the wiper during heavy 5 work conditions, that is with the leading scrubber 10 having engaged debris on the screen to bring into operation the second working surface of the scrubber, and therefore with the support 18'.- ' abutting the cross-piece 4. 10 Figures 6a and 6b illustrate a further embodiment of scrubber 10' having a shorter and more rigid neck 13' than the previously described embodiments. Figure 6a shows the scrubber in a neutral condition when • the wiper assembly is stationary whereas Figure 6b shows 15 the scrubber in a low friction wiping condition with surface portion 16 engaging the screen 15 and about to engage debris thereon. The support 18' is of the type generally shown in Figure 3 with no backing strip but has an integrally moulded neck member 20 to support the 20 removable scrubber 10'. The neck member 20 comprises a slide jaw 7' which receives the beading 14' of the scrubber in a sliding interference fit. The slide jaw 7' is supported from a thickened neck portion 20a depending from the support 18 ' and a reduced thickness neck portion 25 20b of the neck member 20 between the thickened portion 20a and the slide jaw 7'. The support 18' is self supporting relative to the neck 3 (not shown in this figure) but in order to provide additional flexibility therein relative to the blade, a reduced thickness 0 portion 21 is provided in the support.

In the neutral condition shown in Figure 6a the scrubber 10', the slide jaw 7', and the neck portions 20a and 20b are all aligned perpendicular to the screen. However, as soon as the wiper blade is tilted over as 5 motion begins in one direction (as shown in the drawings,

towards the left) -the first low friction surface area 16 of the scrubber engages the screen 15 through the pivotal movement of the support 18* about the neck 3 together with pivotal movement between the neck portions 20a and 20b and flexural movement of the portion 20b as shown in Figure 6b. As in previous embodiments such low friction engagement is functional when the screen is merely wet or, possibly, for removing grease from the screen. The second surface area 17 is for use in heavy duty conditions, such as in removing dirt from the screen 15 and as shown is designed with a coarser, denser pattern of outwardly protruding projections,, which are preferably of nylon, possibly with rubber tips. However the scrubber may be moulded integrally with the support 18 ' and neck member 20 so that it is not removable from the support 18' in which case it will be made wholly of rubber.

Figure 6b shows the leading scrubber about to engage surface dirt 21 on the screen. At this stage, the engagement of the dirt by the surface projections 23 of the second portion 17 of the scrubber increases drag between the scrubber and the screen sufficiently to cause additional pivoting movement of the neck member 20 in the portion 20a. Furthermore, pivotal movement occurs at this stage in the portion 21 of the support member 18" whereby the second portion 17 of the scrubber is permitted to substantially overlie the screen without lift from the support member 18' and thereby provide greater engagement between the dirt 21 and the scrubber. As in previous embodiments the scrubber body 11 is flexible permitting distortion thereof much as shown in Figure 5b when the second working portion 17 is engaged. As soon as the scrubber assembly removes the dirt, or if more than one pass is required, as soon as it passes over the dirt, the friction between the scrubber and the

screen is reduced and the resilience in the portions 21 and 20a as well as in the scrubber itself cause the second surface portion 17 to be lifted from the screen. In this arrangement, it is believed that the blade lip (not shown in Figures 6a and 6b) is not robbed of any appreciable wiper arm pressure since the scrubber support creates added surface pressure during the second stage of scrubbing.

Figures 7a and 7b illustrate a further embodiment and show the tilting action of the blade and support member relative to the screen as the wiper assembly is displaced (to the left in the drawings) . As shown the wiper blade 1 differs in that it has ears 24 to limit the pivotal movement of the blade relative to the support 18 although the limitation could be provided by corresponding ears on the support member or by any other suitable means.

The scrubbers 10' ' are supported from neck members 20' formed integrally with the support 18. The neck members 20' are substantially rigid relative to the support 18 and any pivotal movement therein is minimised. The neck members 20' may terminate in jaw slides similar to those shown in Figure 1 but as shown the neck members 20' are provided with elongate beads 14' and the jaw slides are formed in the scrubbers. The scrubbers 10' ' of generally circular cross-section with projecting formations on only part of the surface defining the second scrubbing portion 17 and are formed of a flexible sponge-like material to function in a similar manner to the scrubber 10 described with reference to Figure 1 except that substantially all of the independent pivotal movement of the scrubbers occurs in the scrubbers themselves, so that in practice the neck members 20' may

be omitted. The smooth first portion 16 of the surface provides a "free-wheeling" function when the screen 15 is wet only.

Figure 7a denotes the first scrubbing stage in which there is no pressure loss from the wiper blade and operates when there is merely water, or possibly also grease, on the screen. As the blade tilts over from its neutral stationary position, the trailing ear 24 engages the support 18 to lift the trailing scrubber 10' ' off the screen. The leading scrubber 10'' is held back by the low frictional engagement with the screen through distortion of the flexible scrubber body and minimal pivotal movement of the neck member 20', but is not held forceably against the screen because it is held relatively freely by the flexible neck 20' and is not abutted by the support 18 in this condition. The distortion of the leading scrubber 10' ' on engagement with the screen allows the tilting of the support 18 and the accompanying layover of the wiper blade without pressure loss from the wiper arm.

As shown in Figure 7b as the leading scrubber 10'' engages debris on the screen the increasingly textured second scrubbing surface 17 of the scrubber is drawn down and rearwardly through drag pulling the support 18 downwardly at its leading end and urging the trailing end against the cross piece 4. As the space beneath the leading end of the support 18 is reduced the leading scrubber becomes compressed between the debris on the screen and the support member to agitate the debris, again with minimal pivotal movement in the neck member 20'. At this stage, there is likely to be some pressure loss between the blade and the screen but this is considered to be permissible in view of the improved temporary heavy duty scrubbing action.

Figures 8 to 11 illustrate wipers in accordance with the invention and similar to those already described with reference to, respectively, Figure 4, Figures 7a and 7b, Figures 5a and 5b and Figure 1 where a support 18 is pivotable about a neck 3 relative to a substantially rigid cross piece 4 with scrubbers depending from the support member 18 in independently pivotable manner. However, the scrubbers in these embodiments are of a different nature. The scrubbers 10* '' may be wholly integrally moulded with the remainder of the wiper or they may be partly integrally moulded with the surface projections being formed on an insert portion (not shown) . The insert portion may be slidably engageable with the integrally moulded portion, and therefore be replaceable, or may be adhesively or otherwise bonded to the integrally moulded portion, and is preferably formed of a relatively rigid material such as nylon or acetal, with the projections 23 also being formed of such material to provide low frictional resistance with the screen but rigid engagement with deposited material on the screen. Each scrubber comprises a relatively rigid body 11' formed of rubber with an arcuate or cam shaped outer surface on which surface projections 23 are formed for engagement with the screen when leading the wiper blade 1. Each scrubber is freely pivotable about a relatively long integrally moulded flexible neck portion 13, although in the neutral condition shown ^' the scrubbers are both raised off the screen in order to permit sufficient pivotal movement of the blade and support 18 in use without the leading scrubber abutting the wiper blade. The full pivotal movement of the leading scrubber is permitted by the inner portion 25 thereof being cut away or reduced. As shown in the figures, the projections 23 become coarser with increasing distance from the screen and as previously described engage the

screen only lightly in the low friction first stage through the portion 16. In the heavy duty second stage, the cut away portion 25 engages the support member 18 to compress the leading scrubber between the support and the screen with the coarse projections in the second portion 17 engaging the screen. The scrubbers are spaced sufficiently from the blade to not abut the blade, and the length of the neck portion 13, the extent of the body 11', the height of the blade, the pivotal movement thereof and any pivotal movement permitted between the slide member 5 and the slide jaw of the wiper arm must all be determined to ensure the correct operation of the wiper assembly under all conditions, including windscreen curvature and varying wiper arm spring pressures. The shape and operation of the scrubbers 10 ' ' ' are similar to that described hereinafter with reference particularly to Figures 20-24.

In Figure 12 an elongate scrubber of substantially hemispherical cross-section is shown, for convenience without surface projections. It will be appreciated that while no surface projections are necessary in the first working surface portion 16, they will normally be provided, although again not essentially, on the second surface portion 17. By having a hemispherical shape the scrubber may be rotated about 180 degrees as in the embodiment described with reference to Figure 1. The body of the scrubber is substantially rigid. Figure 12 shows the scrubber in each of three conditions, from left to right, neutral, the first working condition in which the scrubber is compressed between the screen 15 and the support 18. The scrubber is supported by a flexible neck 20 as in the Figure 6 embodiment, although in this instance the slide jaw is carried by the scrubber as shown in Figure 7. In the first working condition, between 70% and 90% of the wiper

arm pressure may be applied to the blade to perform normal wiping and in the second working condition this may be reduced to 50%. However, there may actually be more pressure applied through the blade tip by the following chain reaction: dirt on the screen causes drag pulling down the leading end of the support and applying axial compression to the leading scrubber; the axial compression is also applied to the blade through the support. In Figure 13 various alternative embodiments of scrubbers are shown schematically without surface projections but with the first and second working portions 16 and 17 thereof being indicated.

Each scrubber may be flexible or substantially rigid, but each provides an effective camming action between the portions 16 and 17. The progression between the portions may be sharp or gradual and the surface portions may be self-cleaning. Thus, the surface may be fully covered with no deep recesses or holes which could embed hard particles. The scrubbers may comprise sponge or foam or be hollow but reεiliently constructed, for example of nylon, in which case small holes may be provided for ejection of water in use.

The self-cleaning aspects of the scrubber could be improved by providing webbing, netting or other form of wrapping around a sponge-like substance, the wrapping being closely textured with small holes to form a filtering screen in order to allow water in but not harder particles which could get caught and thereby scratch the windscreen. The self-cleaning requirements would thus be performed by the jetting effect of the water exiting through the holes. The scrubbing texture could alternatively resemble concave formations with holes in their middles, to which debris would find it difficult to adhere. If the scrubber is not flexible and

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therefore not deformable under compression, a separate actuator or compressor may be actuated by compression against the screen during heavy duty scrubbing. Also, to avoid debris accumulation on the scrubber, the aforementioned webbing may comprise multiple relatively ^" movable layers in the form of over-lapping, slideable textural parts through which water may pass but to which no debris of any kind could stick once water movement (in and out) takes place. In Figure 14, an alternative neck portion 13'' is illustrated which has a tapering inner surface to provide increasing resistance to pivotal movement of the supported scrubber and to alleviate long term bias of the neck member. Figures 15 to 24 described hereinafter are directed to a second type of wiper assembly in accordance with the present invention in which there are provided two wiper blades in spaced side by side array with at least one of the wiper blades carrying on its outer surface a scrubber. The wiper blades are pivotable independently of each other but the or each scrubber is fixed relative to the respective blade. As shown in the drawings, both wiper blades carry a scrubber to provide scrubbing motion in both directions of movement of the reciprocating wiper assembly, but only one need be provided to give a scrubbing action in just one of the directions of movement. Where only one scrubber is provided, in the direction of movement in which there is no scrubbing action both wiper blades will provide a wiping motion.

Referring particularly to Figure 15, two wiper blades 41 and 42 of generally triangular cross-section are supported in spaced side by side manner by respective flexible necks 43 from a substantially rigid support member 44 which is itself rigid with a centrally located

T-piece slide member 45. As in the previously described embodiments, the slide member is held substantially rigid by a suitable claw on a spring loaded wiper arm to hold the wiper against the screen, the wiper arm being reciprocated by a suitable motor to traverse the screen, or part of the screen.

Each elongate wiper blade has on its outer surface a full length longitudinal channel 46 of key slot cross-section in which is received the beaded support 47 of an elongate scrubber 48. Each scrubber 48 may be formed of rubber or a flexible sponge-like material as in previous embodiments and has an outer surface 49 defining projections 50 which are adapted to engage the surface of the screen. The inner surface 51 of each scrubber is contoured to fit the outer surface of the wiper blade and the scrubber is of such a width that it covers substantially the full outer surface of the blade apart from the tip 52 which is in engagement with the surface of the screen 53. The outer surface 49 of the scrubber defines two screen engaging portions 54 and 55 with the portion 54 being adapted to scrub the screen surface under low friction conditions and__may have no projections 50, and the portion 55 being adapted to engage the screen surface under heavy duty conditions such as when the scrubber engages debris on the screen. Accordingly, the surface portion 55 may have coarser projections 50, or there may be otherwise adapted to more strenuously engage the debris. The scrubbers 48 may also be formed of substantially rigid material, such as nylon.

In use, when, for example, the wiper is moved to the left in the drawings, the trailing right hand wiper 42 tilts over by pivoting action in its neck 43 until the trailing upper corner 56 engages the support 44 to provide the optimum wiper angle, pressure from

spring-loaded wiper arm causing the support member 44 to move closer to the screen 53. At the same time, independently of the blade 42, the blade 41 pivots about its neck 43 in the same manner, but in this instance, the surface portion 54 of the left hand leading scrubber 48 engages the surface, and at the same time the blade tip 52 is raised off the screen, or almost off the screen. In these conditions, the upper trailing corner 57 of the blade 41 should be spaced from the support 44 so that minimal pressure is applied to the screen through the portion 54 of the scrubber surface and substantially all the wiper arm pressure is applied to. the trailing blade 42. When the leading scrubber engages debris or other high friction material on the screen, the scrubber motion is restrained and the scrubber pivots further about its neck 43 to bring the second surface portion 55 of the scrubber into engagement with the screen. At the same time, the trailing upper corner 57 of the blade 41 engages the support 44 to apply pressure to the screen through the surface portion 55. At this stage, some of the wiper pressure may be removed from the blade 42 but this is believed to be of little consequence to the wiping action. As soon _as the leading scrubber 48 removes or passes over the debris, the pressure sharing and natural resilience of the neck 43 moves the scrubber back into its first scrubbing position in which the surface portion 54 engages the screen. At the end of the sweep, when the wiper begins to move in the opposite direction, the blades 41 and 42 pivot independently to tilt in the opposite direction and the same action is provided by the opposite blades. Instead of having one slide member 45, it may be preferred to utilise two, spaced side by side on the support member. It will be

appreciated that the scrubber assemblies 48 extend the full length of their respective blades and may be removed if they become worn, to be replaced by new ones.

In the embodiment illustrated in Figure 15, the wiper blades 41 and 42, the flexible necks 43, the substantially rigid support 44 and the slide member 45 are all integrally moulded in rubber to provide a unitary construction, and the scrubbers 48 could also be integrally moulded. The rigidity of the support 44 may be provided by a thickening thereof or by moulding therein a separate plate.

A second embodiment of the second type of wiper in accordance with the present invention is shown in Figures 16a and 16b with Figure 16a showing the wiper assembly in a first low friction condition and Figure 16b showing the wiper assembly in a heavy duty scrubbing motion, in both cases with the wiper moving towards the left in the drawings. In this embodiment, the wiper blades 41' and 42' are supported by their flexible necks 43 from an integrally moulded flexible support member 58, although in practice the blades and necks would be closer together than as shown. The necks 43 are continued above the support member 58 to define head portions 59 which are received through cooperating openings in a rigid plate 60 from which the wiper is suspended from the wiper arm in a manner not shown. The wiper blades 41' and 42' have integrally moulded therewith in rubber cam shaped scrubbers 49' which are slightly flexible and which define two working portions 54' and 55' of the surface. The upper inner corners 57' of each wiper blade are reduced by rounding off in contrast to the wiper shown in Figure 15 for no engagement with the support member 58 in the first scrubbing condition but engagement therewith in the second scrubbing condition shown in .Figure 16b, but otherwise the wiper functions in identical manner to that

shown in Figure 15. Alternatively, the scrubbers may be separate but bonded to or otherwise engaged with the blades. As in the Figure 15 embodiment, the distance between the reduced inner corner 57' and the portion of the second scrubbing surface 55* engaged by the screen in the second scrubbing condition must be greater than the distance between the support 58 and the screen 53 in said condition in order to provide the compressive force to the scrubber. To counter long term bias in the necks 43, they may be tapered in the manner proposed in Figure 14. The lip 52 ' may also be extended further beyond where the scrubber joins the blade body to enable sufficient lay¬ over thereof and enhance the pivoting action of the blade bodies. Figures 17 and 18 illustrate embodiments of wiper similar to that described in Figures 16a and 16b but modified in the upper inner corner 57' of the blade to provide the engagement with the support member 58. In the embodiment shown in Figure 17, the support member 58' is held against the rigid plate 60 by a single engaging member 59' located centrally between the necks 43 and the blades pivot independently not only about their necks 43 but also about a reduced thickness portion 61 located substantially opposite the point of engagement with the support member of the inner upper corner 57' or between said point and the engaging member 59 ' .

In Figure 18 the engaging member 57' comprises an ear. In both these embodiments, some pressure loss from the wiper blade 41' or 42* to the other scrubber 48' may occur even during the first working condition of the scrubber but this may be of advantage for degreasing the screen during said first condition. Figure 17 shows the scrubber entering the second working condition with

flexing about the portion 61, and the same condition is entered with the Figure 18 embodiment by controlled flexing of the ear 57'.

Figure 19 shows an embodiment in which an ear 72 is provided on the outer upper corner of the blade body to control the tilting of the body during the blade wiping action. By this arrangement much the same action is provided as in the embodiment of Figures 16a and 16b, but in this case there is no requirement to reduce the inner corners 57' and the ear 72 allows for wider scrubber profile to be used.

Figures 20 to 24 illustrate further embodiments of the second type of wiper in accordance with the invention and generally illustrated in Figure 15 but using the principles established in the embodiments of Figures 8 to 11. Thus, the wiper shown in Figure 20 has a substantially rigid integrally moulded rubber support member 44 which is supported on a wiper arm by the slide member 45 and from which depend two spaced wiper and scrubber assemblies 62. The assemblies 62 are supported by flexible necks 43 and in the neutral condition shown, the blades 63 are aligned with the neck members 43. The scrubber portion 64 of the assembly 62 is generally similar to the scrubber 10' ' ' of Figures 8 to 11 and is defined by a 90 degree sector whose centre of rotation is defined by the junction of the neck member 43 with the assembly 62. On its side opposite the scrubber portion 64, the assembly 62 has a portion 65 of conical cross- section whereby in heavy duty conditions previously described, with the associated second portion 64b of the scrubber engaged with the screen to remove debris therefrom, the neck 43 flexes so that it is trailed substantially parallel with the support member 44 and the upper inner surface 66 of the cone portion 65 also extends in said direction with the cone tip 67 engaging

said support member 44 to apply pressure onto the screen surface through the second portion of the scrubber. The two assemblies 62 must be sufficiently spaced to permit said alignment of the neck 43 and surface 66 with the support member without substantially affecting the f nction of the wiper 63 of the other assembly 62. When the wiper 63 of the respective assemblies 62 is in use, the outer corner 68 of the sector scrubber assembly abuts the support member 44 to define the pivot angle of the wiper. It is to be noted that in the neutral condition both scrubber portions 64 are raised from the screen and that in the first operating condition through the first scrubber portion 64a substantially all of the pressure applied by the wiper arm through the wiper assembly to the screen is applied through the trailing wiper 63.

In Figures 21 and 22 various modifications to the embodiment in Figure 20 are proposed to permit the pivotable movement of the assemblies 62. In each of the three embodiments of Figures 20-22, the scrubber portion is integrally moulded with the remainder of the wiper in rubber and is relatively solid. The scrubber surface may define different or coarser projections between the first and second scrubber areas as previously suggested and it will be noted that the scrubber surface is also integral with the wiper, although the scrubber surface may be bonded to the assembly.

As illustrated in Figure 23, the assembly 62 has been modified whereby the scrubber portion or surface 64' is removable, the assembly 62 defining a slide member 69 on which the slide jaws 70 of the portion 64' are received in sliding manner. The scrubber portion 64' may be formed in a rigid plastics, for example nylon or acetal, and defined on its scrubbing surface are elongate razor-blade like formations 71 whose angle of projection vary according to the position around the arc

generally by the scrubber surface. The blades 71 are designed to engage the surface of the screen in use at respectively between 25 degrees and 35 degrees to efficiently scrape debris from the screen. It will be noted that no blade is provided immediately adjacent the wiper blade 63 since this portion does not come into contact with the screen. Preferably the blades are designed to be self sharpening upon movement across the screen. In the embodiment illustrated in Figure 23, the assemblies 62 are located relatively close to one another and in use the leading, non-wiping blade 63 will abut the tip 67 of the conical formation but it is believed that this will be substantially without affecting the operation of the trailing wiper blade since the angle of the wiper body is held substantially rigid by the slide member 45, and the upper surface 68 of the trailing scrubber member 64 ' engages the support member 44 to define the working angle of the trailing blade 63.

The working angle of the trailing blade and leading scrubber is dependent upon the windscreen curvature as well as any give in the mounting of the wiper assembly to the wiper arm. The operation of the wiper of Figure 23 is shown schematically under extreme conditions in Figures 24a and 24b where the wiper in both cases is being moved to the right in the drawing and the blade-like formations 71 on the scrubber are not shown. In Figure 24a the wiper assembly is shown at extreme curvature of the screen 53, with the curvature being such that the second working portion of the leading scrubber is in engagement with the screen, but with the friction between the screen and the scrubbers still relatively low so that the leading blade 63 is not being forced heavily against the trailing blade body. In Figure 24b the frictional drag has been increased and the tip portion 67 of the leading blade has been forced against the trailing

neck 43 and support member 44 and the leading blade 63 has been curved around the trailing tip portion 67. It will be appreciated that the trailing blade is still at an optimum wiping angle although there is now substantial pressure sharing with the leading scrubber. The engagement between the leading wiper blade 63 and the trailing blade body necessitates a relatively flexible blade 63 and for this reason the blade is made relatively long Similarly, the degree of pivotal movement in the neck 43 requires substantial flexibility and therefore increased length may be desirable. Preferably, as shown, the combined length of the neck portion 43 and of the surface of the conical abutment formation between the neck and the tip 67 are substantially the same as the separation of the two neck portions 43.

It will be appreciated that many other embodiments of wiper assembly in accordance with the invention have not been described, and that many of the parts described herein may be introduced as alternatives on other embodiments also described. Other modifications may be made to the support body by providing flairings to control windflow over the wiper assembly and therefore downward pressure of the_ assembly on the screen.

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