GB2132077A - Brush attachment for windscreen wiper - Google Patents

Abstract

A brush attachment for a windscreen wiper comprising a wiper arm 13 and wiper blade 11 comprises at least one bristle strip 27 and clips 35 for securing it to the wiper. The clips 35 may project from a backing member 31, may be resiliently deformable or malleable, and may be formed of metal or polymeric material, or both. <IMAGE>

Description

SPECIFICATION Attachment for windscreen wiper This invention relates to an attachment for a windscreen wiper.

With the advent of high speed travel, either by motor vehicle, or by train or by air, it is important that the driver's forward vision is not impaired.

Accordingly, considerable effort has been expended recently to ensure satisfactory vision, even in foul weather, and especially after the vehicle windscreen has been struck by flying insects, or vision has been reduced, for example, as a result of dirt being thrown onto the windscreen.

Most vehicles are now fitted with screen washing devices, but the traditional elastomeric wiper blade is not always able to remove dead insects, dirt and other undesirable matter from a windscreen, even if it is thoroughly wetted with water from the screen washing device.

Attempts to solve these problems have been made, either by means of special wiper blade constructions, incorporating in-built scraping or brush devices, andlor by feeding washing fluid to the wiper blade itself. In some cases, improvements in the cleaning capacity of the wiper blade have resulted, but unfortunately, such special systems are complicated to manufacture and install, and are thus very expensive.

We have now devised an attachment for most types of windscreen wiper which results in considerable improvement in the cleaning of the screen, and which is used in conjunction with existing screen washing facilities. The attachment is relatively inexpensive to manufacture, and can be fitted by any vehicle owner.

According to the present invention, we provide an attachment for a windscreen wiper comprising a strip of bristles, and means for connecting the bristle strip to the wiper.

Preferably, the attachment is connected to the wiper blade.

In one construction, the attachment comprises a continuous strip of bristle material connected to or extending from the means for connecting the attachment to the wiper. However, most modern screen wiper blades are designed with two wiping edges at their operative face and hence rock to and fro with each sweep of the blade to and fro across the screen.

Ideally, therefore, two attachments are fitted to each wiper, although it is envisaged that an attachment to the wiper, with one strip on each side of the wiper, could be provided.

In one construction, the means to connect the attachment to the wiper comprises an easily deformable comb-like strip which can be fitted around the wiper. This strip may be injection moulded from a synthetic resinous material, such as polypropylene, but is preferably extruded and punched into the required form.

In one construction, when the attachment is fitted to a wiper and viewed from one end, it will appear arcuate in cross-section, the arc defining the major portion of a substantially circular or elliptical figure, with the strip extending generally tangentially from the arc towards one end of the arc, and attached thereto along a rear edge.

Preferably, the or each bristle strip is formed from lengths of bristle formed of synthetic resinous material, which bristle lengths are maintained in strip form by a backing strip of identical or compatible synthetic resinous material. This backing strip is preferably formed by passing the bristles through an extruder, which heats their non-wiping ends, whereupon the synthetic resinous material is extruded over the aligned heated ends in the form of a bead and subsequently allowed to cool, thus forming a unitary bristle strip. However, many other brush strip constructions are possible.

Preferably, the means to connect the attachment to the wiper is also formed of a synthetic resinous material compatible with that of the bristles and/or bead, and it is envisaged that it could be extruded in a single extrusion operation with the bead, whereupon it would subsequently be punched to give the comb-like configuration.

In one construction, the said means could have some degree of resiliency, so that it will grip around the wiper and yet so that its arcuate shape can be "sprung" open to allow it to be fitted around the wiper. A metallic carrier formed of spring steel or the like may therefore be incorporated within the web, or the polymeric material itself may be resiliently deformable.

In an alternative construction, the said means may be of a maleable nature, and this may be achieved by incorporating a suitable carrier formed of a maleable metal, e.g. wire or stamped sheet metal, within the polymeric material.

It is also envisaged that the brush strip could be connected directly to one edge of a deformable metallic carrier which itself forms said means.

Most modern windscreen wiper blades are of generally cruciform-shaped cross-section, with the longest arm of the cruciform being the wiping arm,, and the other arms being formed for connection to a metallic holder. These may be several parallel cross arms.

Accordingly, it is preferred that when the attachment of this invention is fitted to the blade, the tips of the (or one of the) cross bar(s) of the cruciform will bear against one end of the said means from which the bristle strip projects. Since the blade is normally formed of rubber or other elastomeric material, the tip will therefore alternately tend to press the bristle strip against the windscreen, and then allow it to lift off the windscreen, as the blade rocks to and fro during its sweeps across the screen. Hence, when the strip is pressed against the windscreen, pressure from the spring steel forming part of the wiper is transmitted to the strip.

Two embodiments of a wiper attachment in accordance with the invention are now described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a portion of a first embodiment attached to a windscreen wiper; Figure 2 is a transverse section through the assembly shown in Figure 1 and showing the assembly moving in one direction across a screen; Figure 3 is a view similar to Figure 2 but showing the assembly in a neutral position at the end of its wiping stroke as it rocks over to start a return wiping stroke, and Figures 4 and 5 are views similar to Figures 2 and but of a second embodiment of the invention.

In the drawings, like parts are identified by the same reference numerals.

Referring to the drawings, a traditional windscreen wiper blade 11 is shown mounted on a windscreen wiper arm 13 of known construction, the arm 13 in conjunction with spring metal strips 15 biasing the tip 17 of the blade 11 into engagement with a windscreen represented at W in Figures 2-5. As can be seen, the blade 11 has a generally cruciform shaped section with the longest arm terminating in the wiping tip 17 and the other arms inluding three generally parallel cross arms 19,21 and 23 being connected at spaced intervals to stirrup shaped holders 25 of the wiper arm.

A first embodiment of attachment according to the invention is shown generally at 27 in Figures 1-3 and comprises a brush like strip formed of a plurality of bristles 29 held together along their non-wiping edge by a backing member 31. The backing member 31 is connected to means 33 for connecting the strip to the wiper and as shown, the means 33 is comprised of a plurality of arcuate clips 35 which engage around the arms 19,21 and 23 of the blade 11.

The brush strip 27 may be secured to the means 33 in any known manner but it is preferred that the strip 27 and means 33 are each formed of synthetic resinous material and in one construction, therefore, the spaced clips 35 are injection moulded in one piece with at least one spine connecting them together and are then adhered or heat sealed, for example along the spine, to the backing strip 31. In the most preferred construction, however, the bristles 29 and the backing strip 31 are formed of compatible polymeric materials and the backing strip 31 is extruded onto the non-siping ends of the bristles 29, for example by pre-heating the nonwiping ends of the bristles 29 and then passing them through an extruder so that the strip 31 which is in the form of a bead, is integral with the bristles.In this construction the means 33 can be extruded at the same time as the bead 31 from the same material or, alternatively, can be formed in a separate extrusion operation and then be adhered in known manner to the strip 31. Regardless of how the means 33 is extruded, it will of course emerge from the extrusion die as a continuous mass of polymeric material and in order to convert it from a continuous mass into the spaced clips 35 which would either be connected together by the spine (not shown) or by the strip 31, the continuous mass would be subjected to a punching operation which could be in line with the extruder so as to punch out portions of the mass between the clips 35.

Each clip 35 (and, if it is extruded, the remainder of the means 33 emerging from the extuder die) is formed of a deformable material. In one construction this deformable material may be malleable, in which case the means 35 could be extruded or moulded so as to have a cross-sectional shape different from that shown in the drawings and when it is desired to fit the attachment to a windscreen wiper, the clips 35 could be manipulated from their manufactured shape so as to embrace the wiper blade 11 although it is essential that the two end portions 37 and 39 of the clips are inturned so as to engage beneath the cross arm 19 of the blade 11 or, alternatively, so as to engage in the spaces between the cross arms 19 and 21.To achieve this, therefore, it is preferable that the end portions 37 and 39 are pre-formed so as to extend at approximately 120 to their adjacent clip portions. If the clips 35 are formed of a maleable material they could of course be formed of soft metal rather than polymeric material but in a preferred arrangement, they are formed of polymeric material surrounding a soft metal carrier. The soft metal carrier may be of any known construction sudr as the well known Schlegel knitted wire carrier of generally zig-zag configuration held in that position by longitudinal textile or other warp members.

Instead of being malleable, the clips 35 may be resiliently deformable. Again, they may be formed of a springy metallic material but it is preferred they are formed of a resiliently deformable polymeric material, or, alternatively, from a polymeric material incorporating a resiliently deformable carrier formed of springy metallic material such as our own knitted wire carrier which in this case, instead of being formed of malleable wire would be formed of spring steel wire. Obviously, if metallic carrier is incorporated in the means 33, this could be surrounded by a polymeric material by passing the carrier though a cross head extruder although of course it would then be necessary to carry out a punching operation which would not only remove portions of polymeric material but also portions of the carrier.

Suitable polymeric materials for the means 33 are polyolefins, nylons, PVC's, polystyrenes and combinations of these such as, for example, block copolymers, or rubber modified versions of the polymers. Alternatively, it is envisaged that a slotted metal or knitted wire carrier alone could provide the means 33.

The construction shown in Figures 4 and 5 differs from the construction shown in Figures 1-3 in that instead of being provided with a single brush strip 27, a pair of brush strips 27 and 28 are provided, with one located on either side of the clips 35.

It is important that the clips 35 are so designed that their end portions 37 and 39 are in engagement with one of the cross arms 19 or 21 of the windscreen wiper blade 11.

As can be seen from the drawings, when the wiper is in use and is moving across the windscreen W with a wiping action in the direction of the arrow A, the brush strip 29 is designed to engage the screen W and brush or scrape dirt on the screen so as to loosen it prior to the blade tip 17 wiping it from the field of vision. Modern windscreens are often curved and this explains the complicated design of the blade and the wiper arm, the intention being that regardless of the shape of the windscreen, the leading edge of the tip of the wiper blade will always be biassed into wiping engagement with the screen.

Obviously, for the attachment of the present invention to operate satisfactorily it is therefore important for the tips of the bristles also to brush across the screen during every wiping stroke of the wiper in the direction of the arrow A. By arranging for the arms 37 and 39 to engage beneath one of the cross arms 19 or 21, this is achieved. As can clearly be seen from Figures 2 and 4, as the wiper moves in the direction of the arrow A, the blade will tilt over slightly so that the right hand limb 20 of the arm 19 moves closer to the windscreen W than the left hand limb 22 and as it tilts over so the limb 20 will bear onto the end portion 39 of each clip 35 thus ensuring that the bristles 20 bear against the screen W.By arranging for the bristles 29 during this wiping action to extend generally normal to the windscreen W, the bristles will tend to walk across the screen thus ensuring that any dirt brushed from the screen by the bristles will automatically be flicked loose from the bristles, thus preventing clogging.

When the wiper reaches the end of its wiping stroke, it will momentarily stop, rock through the neutral position shown in Figure 3 thus causing the bristles 29 to be lifted from the screen W and will then move in the opposite direction to the arrow A, during which time the blade 11 will merely wipe across the screen. If, however, an attachment with two brush strips 27 and 28 is fitted to the windscreen wiper, then as the wiper starts to move back across the screen so the second brush strip 28 will move down into engagement with the screen and be held in engagement with the screen by the limb 22 of the cross arm 19 thus ensuring a brushing action during all wiping strokes of the wiper.

As an alternative to fitting an attachment with one brush strip 27 shown in Figures 1-3 or the attachment with two brush strips as shown in Figures 4 and 5, two attachments with single brush strips 27 may be fitted due to the comb-like nature of the means 33. Simply by reversing an attachment such as that shown in Figure 2 so that its strip 27 is on the left hand side of the wiper rather than on the right hand side of the wiper as shown in Figure 2 and by locating the clips 35 of the attachment in the gaps between the clips 35 of the attachment shown in Figures 1-3, this is simply achieved.

It will of course be appreciated that the clips 35 may have shapes other than that shown in the drawings but it is an important preferred feature of the invention that they are designed with end portions which engage with limbs of one of the cross arms provided on modern-day wiper blade so as to bias the or each brush strip of the attachment into engagement with the windscreen during use and so as to lift off any brush strip trailing the wiper blade so as not to leave smears.

Windscreen wiper attachments as described above are of course relatively simple and inexpensive to manufacture and due to their resiliently deformable nature can easily be attached to most if not all constructions of modern windscreen wipers.

They can therefore be marketed either as a standard feature or an extra feature on a new car or, alternatively, can be sold in most accessory shops for attachment to existing windscreen wipers.

It is of course envisaged that the attachments as well as being useful on motor vehicles could also be fitted to windscreen wipers of other vehicles.

Claims (22)

1. An attachment for a windscreen wiper comprising a strip of bristles, and means for connecting the bristle strip to the wiper.

2. An attachment according to claim 1 wherein the connections means is adapted for connection to the wiper blade.

3. An attachment according to claim 1 or 2 and further comprising a strip of bristle material substantially equal in length to a blade of the wiper connected to or extending from the means for connecting the attachment to the wiper.

4. An attachment according to claim 1,2 or 3 wherein two bristle strips are connected to or extend from the means to connect the attachment to the wiper, with one bristle strip adapted to be located on each side of the wiper.

5. An attachment according to any one of claims 1-4 wherein the means to connect the attachment to the wiper comprises an easily deformable comb-like strip which can be fitted around the wiper.

6. An attachment according to claim 5 wherein the strip is injection moulded from a synthetic resinous material.

7. An attachment according to claim 5 wherein the strip is extruded and then punched into the required form.

8. An attachment according to claim 6 or 7 wherein, when the attachment is fitted to a wiper and viewed from one end, it will appear arcuate in cross-section, the arc defining the major portion of a substantially circular or elliptical figure, with the strip extending generally tangentially from the arc towards one end of the arc, and attached thereto along a rear edge.

9. An attachment according to any one of claims 1-8 wherein the or each bristle strip is formed from lengths of bristle formed of synthetic resinous material, which bristle lengths are maintained in strip form by a backing strip.

10. An attachment according to claim 9 wherein the backing strip is formed of identical or compatible synthetic resinous material to that of the bristles and is formed by passing the bristles through an extruder, which heats their non-wiping ends, whereupon the synthetic resinous material is extruded over the aligned heated ends in the form of a bead and subsequently allowed to cool, thus forming a unitary bristle strip.

11. An attachment according to claim 9 or 10 wherein the means to connect the attachment to the wiper is formed of a synthetic resinous material compatible with that of the backing strip.

12. An attachment according to claim 9, 10 or 11 wherein the connecting means is extruded in a single extrusion operation with the backing strip and is subsequently punched to give a comb-like configuration.

13. An attachment according to any one of the preceding claims wherein the connecting means is resilient so that it will grip around the wiper and yet can be deformed temporarily to allow it to be fitted to the wiper.

14. An attachment according to any one of the preceding claims, wherein the connecting means incorporates a metallic carrier formed of spring steel orthe like.

15. An attachment according to any one of claims 1-13 wherein the connecting means is formed of polymeric material which is resiliently deformable.

16. An attachment according to any one of claims 1-13 wherein the connecting means is of a maleable nature.

17. An attachment according to claim 16 wherein a carrier formed of a maleable metal is incorporated within a polymeric material to provide said connecting means.

18. An attachment according to claim 14 or 17 wherein the bristle strip is connected directly to one edge of the metallic carrier which itself forms said connecting means.

19. An attachment according to any one of claims 1-4 wherein the connecting means comprises one or more screws, rivets, bolts or the like, or an adhesive.

20. An attachment for a windscreen wiper, substantially as hereinbefore described with reference to the accompanying drawings.

21. A windscreen wiper wherein the wiper blade is formed of elastomeric material and is of generally cruciform-shaped cross-section with the longest arm of the cruciform being the wiping arm, and the other arms being formed for connection to and connected to a metallic holder, in combination with an attachment as claimed in any one of the preceding claims, wherein the tips of the cross arms of the cruciform are in engagement with said connecting means from which the bristle strip projects, the arrangement being such that, in use, the said tips will therefore alternately tend to press the bristle strip against the windscreen and then allow it to lift off the windscreen as the wiping arm rocks to and fro during its sweeps across the screen.

22. Awindscreen wiper having an attachment incorporating at least one bristle strip connected thereto, substantially as hereinbefore described with reference to the accompanying drawings.