GB2326083A

GB2326083A - Wet arm windscreen wiper/washer, with alternating spray direction

Info

Publication number: GB2326083A
Application number: GB9811120A
Authority: GB
Inventors: Peter Munroe Smith
Original assignee: Trico Products Corp
Current assignee: Trico Products Corp
Priority date: 1997-05-26
Filing date: 1998-05-26
Publication date: 1998-12-16
Also published as: GB9811120D0; AUPO696897A0

Abstract

The specification discloses a wet arm type vehicle windscreen cleaning system 10 including liquid delivery nozzle outlets carried by a wiper drive arm 2, the nozzle outlets being supplied with pressurised cleaning liquid from a reservoir 11 by a pump P such that washing liquid, when it is supplied in use, is delivered in a stream, or separate streams only in front of a wiper blade 3 of the cleaning system 10 regardless of the direction of movement of the wiper blade 3. In the embodiment shown a switching valve 26 is incorporated and switches the supply of cleaning liquid from one side of the blade to the other in response to the control means 19 associated with wiper drive motor 21.

Description

"Improvements relating to apparatus for washing a windshield of a motor vehicle" The present invention relates to improvements in apparatus for washing a windshield of a motor vehicle.

Conventionally, windscreen washing apparatus can typically be categorised into two types, namely a first type where spray nozzles for the washing liquid are fixed in position at a location or locations separate from and normally in front of the vehicle windscreen such that the liquid stream from the spray nozzles generally flows with the direction of air flow over the windscreen. Such spray nozzles normally supply washing liquid to a relatively wide region of the windscreen and is further distributed across the windscreen by oscillating passage of wiper blades of the windshield wiper system. The second arrangement type is where spray nozzles are mounted on or with the wiper arms of the windshield wiper system and thus move with the wiper arms. Typically such spray nozzles, when operating, spray washing liquid continuously on both sides or one side only of the wiper blade. This second arrangement type is commonly known as a "wet" arm arrangement.

Modern day vehicles commonly have vehicle windscreens that are curved both in a transverse direction of the vehicle and also in a vertical or longitudinal direction of the vehicle.

To cope with such windscreens, wiper blades are typically made flexible and are supported by a harness structure that is pivoted to the free end of the oscillating wiper arm, the harness structure being configured to apply a number of separate and spaced pressure application points to the wiper blade to maintain the wiper blade in contact with the vehicle windscreen during oscillating movement of the wiper arm.

Furthermore, modern day vehicles operate at relatively high speeds and it is necessary for the windscreen wiper system including any washing liquid supply mechanism to operate satisfactorily at at least the maximum speed permitted on the road system, for example 110 km/hour. There are of course also several other factors that are relevant to the viability and correct operation of a windscreen cleaning system. Firstly, it is of course necessary that the system be able to remove or clear any liquid including applied cleaning liquid on the windscreen within a relatively short period of time so as not to obstruct the driver's viewing capabilities. Secondly, of course, any applied cleaning liquid should be effective in the efficient cleaning of the windscreen.

U.S. Patent Specification Nos. 2,978,728, 2.986,761 and 3,011,199 disclose fix nozzle arrangements of the type generally discussed above. U.S. Patent Specification No.

2,582,717 discloses a wet arm type arrangement as discussed above adapted for use on flat windscreens or the like where the washing liquid is supplied to a lengthwise passage in a head portion of a wiper blade which is itself held within a rigid casing. The washing liquid is supplied continuously, when in use, to both sides of the wiper blade through a plurality of spaced passageways with the passageways on the rear side of the wiper blade relative to the blades direction of movement being said to close due to the resilience of wiper blade material.

This arrangement has a number of disadvantages including the fact that the rear side passages may not close thereby supplying too much washing liquid to the windscreen. Further, the construction requires a specific type of wiper blade configuration and the wiper blade is essentially rigid making it unsatisfactory for curved windscreens. U.S. Patent Specification No. 2,632,911 discloses an arrangement where a liquid stream from a single outlet impinges onto the back surface of a rigid blade holder and is deflected therefrom onto the windscreen in a direction depending on the directional movement of the blade. Such an arrangement is capable only of use on flat windscreens with washing liquid being delivered only to a small area of the windscreen and again also suffers from the problem. of having to provide a specially configured or non-standard type wiper blade. U.S. Patent Specification Nos.

2,562,819 and 2,173,021 are also different configurations where washing liquid is directed to one side or the other by being delivered onto formations of the wiper blade or its backing casing and generally suffer from the disadvantages discussed above with reference to U.S. Patent Specification No.

2,632,911.

Thus an object of the present invention is to provide an improved windscreen cleaning system for a windshield of a motor vehicle which affords improved visibility during cleaning of the windshield.

A further objective of the present invention is to provide an improved windscreen cleaning system for a windshield of a motor vehicle which enables an efficient use of washing liquid during washing of the windshield.

To this end, the present invention, in one aspect, provides a windscreen cleaning system for delivering one or more washing liquid streams onto a vehicle windscreen, said windscreen cleaning system including a means for alternating the direction of the washing liquid stream or streams so as to be located only forwardly of a wiper blade throughout a wiping cycle of the wiper blade.

The present invention also provides a windscreen cleaning system for a motor vehicie, said windscreen cleaning system including wiper means having at least one wiper arm and at least one flexible wiper blade pivotally connected to the or each said wiper arm via a harness adapted to apply windscreen contacting forces to said wiper blade at spaced positions along the wiper blade, said windscreen cleaning system further including washing liquid supply means co-operable with said wiper means having a washing liquid nozzle means carried by said wiper means and washing liquid delivery means for delivering pressurised washing liquid to said washing liquid nozzle means whereby, in use of the washing liquid supply means, one or more pressurised washing liquid streams are applied to a windscreen of the motor vehicle, said washing liquid supply means further including control means for alternating the direction of the washing liquid streams such that washing liquid is only directed forwardly of a said wiper blade onto said windscreen nf the motor vehicle regardless of direction of movement of the wiper blade, said washing liquid stream or streams having a velocity sufficient for the washing liquid to strike the windscreen of the motor vehicle when the motor vehicle is moving at a maximum legally allowed speed (for example 110 km/hour).

Conveniently, the washing liquid nozzle means provides at least two spray nozzle delivery outlets directed on each side of the wiper blade. The washing liquid streams delivered by each of said delivery outlets forming an angle of no more than 450 with a plane at 900 to the windscreen at a point of contact of the stream with the windscreen preferably the aforementioned angle is no more than 300. Conveniently, at least three spray nozzle delivery outlets are provided on each side of the wiper blade providing spaced washing liquid windscreen contact points with the outermost said contact points being separated by at least 50% and preferably at least 70 of the length of the wiper blade. preferably the velocity of the washing liquid stream or streams is at least 5 m/sec and preferably in the range of 5 to 15 m/sec. More particularly the velocity of the washing liquid is in the range of 7 to 9 m/sec.

In one preferred embodiment, the washing liquid nozzle means is carried by the or each said wiper arm with said spray nozzle delivery outlets being located no further outwardly from the vehicle windscreen in a perpendicular direction than the wiper arm. Preferably the spray nozzle delivery outlets may be located between the wiper arm and the wiper blade. In one further possible embodiment, the washing liquid nozzle means might be carried by the wiper blade.

Throughout this specification including the accompanying claims, terms such as "windscreen" or "windshield" are intended to refer to any vehicle glass panel located either forwardly or rearwardly in a motor vehicle on which a cleaning system according to this invention is intended to operate.

Advantageously, by ensuring that the washing liquid is only directed in front of the wiper blade throughout its cycle, the period of time during which the windshield is wet but unwiped is significantly reduced. This in turn improves visibility through the windshield during the washing process.

The apparatus also makes more efficient use of washing liquid by reducing the time that washing liquid is on the surface of the windshield before the wiper blade passes over the wet area, thus increasing visibility without sacrificing efficiency and effectiveness of the cleaning effect of the washing liquid.

The invention may be performed in various ways and a preferred embodiment will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates schematically a windshield cleaning system according to the present invention, the wiping arrangement of the cleaning system being depicted during an upstroke of a wiping cycle; Figure 2 is a view similar to Figure 1 but showing the wiping arrangement during a downstroke of a wiping nozzle; Figures 3, 4 and 5 show in block diagrammatic form various possible alternative arrangements of a cleaning system according to the present invention; Figures 6, 7 and 8 illustrate in plan, side and end views a preferred form of washing liquid nozzle means including spray nozzle delivery outlets that is connectible to the wiper arm or arms; and Figure 9 is a cross-sectional view of the washing liquid nozzle means of Figures 6 to 8 in a position of use.

Referring to Figure 1, a windshield 1 of a motor vehicle is depicted. The wiping mechanism for the windshield includes a pair of wiper arms 2 to which are pivotally mounted wiper blades 3 via a harness structure distributing contact forces along the blades. It will of course be recognised that in any particular application utilising only one wiper arm 2 and one or more wiper blades 3, is also within the scope of this invention. The wiping mechanism is depicted during an upstroke of the wiping cycle of the mechanism wherein the wiper arms 2 move upwardly away from the lower edge 4 of the windshield as indicated by the arrows.

The wiper arms 2 are of the so-called "wet arm" type such that a washing liquid nozzle means 5 for spraying washing liquid onto the surface of the windshield is located on each wiper arm 2 adjacent the wiper blade, i.e. adjacent the free ends of the wiper arms 2.

In accordance with the present invention, the spray 6 from each washing liquid nozzle means 5 is directed only forwardly of-its associated wiper blade 3 so that the washing liquid is sprayed only onto the region of the windshield which is to be wiped during the upstroke of the wiper arm.

With reference to Figure 2, the wiping mechanism is depicted during a downstroke of a wiping cycle. During this phase of the cycle the spray or washing liquid stream 6 from the washing liquid nozzle means 5 is again directed forwardly of the wiper blade 3 so that the washing liquid contacts only onto a region of the windshield which is to be wiped during the downstroke of the wiping arm.

Referring now to Figure 3, there is shown schematically in block diagram format the various integers making up a windscreen cleaning system according to one preferred embodiment of the present invention. The cleaning system 10 includes a washing liquid holding tank or reservoir 11 and a pump 12 which may be a dual flow submersible pump locatable within the reservoir 11. The pump and its drive means may of course also be located external to the reservoir 11. In this configuration the pump 12 delivers cleaning liquid via delivery tubing 13, 14 and branch tubing sections 15, 16, 17, 18 to spray nozzle outlets on either side of the nozzle means 5 as described hereinafter. Direction of rotation of the pump 12 determines whether pressurised liquid flow is provided along delivery tube 13 or delivery tube 14 and functioning of the pump is controlled by control means 19 associated with drive motor means 21 and the wiper arms which provides signals to the pump 12 via line 20 depending upon the direction of movement of the oscillating wiper arms. The wiper arms may of course be driven either by two separate drive motor means or by a single drive motor means 21 with appropriate connecting linkages transmitting oscillating movement to the wiper arm drive shafts.

Figure 4 illustrates a possible alternative arrangement where the single dual action pump 12 is replaced by two separate pumps 22, 23.

Figure 5 illustrates a still further possible arrangement where a single pump 24 is utilised providing pressurised washing liquid via tubing 25 to a switch valve 26. The valve 26 either directs the washing liquid to delivery tubing 13 or 14 in response to signals received along line 20 from the control means 19.

Figures 6, 7 and 8 illustrate a preferred form of washing liquid nozzle means 5 that is fixable to the free end region of the wiper arms 2. The nozzle means 5 comprises two opposed side parts 36, 37 each with an inlet connection 27, 28 and each of which is connectible to the downstream end of one of the branch tubing sections 15, 16, 17 or 18. In this way cleaning liquid can be delivered via internal passage means 29, 30 which also communicate with nozzle delivery outlets 31, 32, 33 and 34, 35, 36 respectively. The washing liquid nozzle means 5 also includes a web section 38 joining the side parts 36, 37 with the side parts 36, 37 each having an inwardly directed lip 39; 40 to enable the nozzle means 5 to clip over a wiper arm section. The inner surface of the web section 38 conveniently includes a projection 41 engageable with an aperture in the wiper arm to prevent the nozzle means 5 from sliding along the wiper arms 2.

Figure 9 illustrates in cross-section the washing liquid nozzle means 5 connected to a wiper arm 2. The wiper arm 2 has a conventional harness structure 41 comprised of a number of pivoted yokes 42 and 43. A flexible wiper blade 3 is connected to the yokes 43 with the rubber element 44 of the wiper blade 3 being maintained in contact with the windscreen 1. The liquid streams 6 exiting from the outlets 31 to 36 are directed downwardly towards the windscreen 1 such that at the contact point with the windscreen they form an angle of no more than 450 to a plane 45 perpendicular to the windscreen surface.

Preferably the angle is no more than 300.

As will be seen in Figures 6 to 8, nozzle delivery outlets 31, 32 and 33 and 34, 35 and 36 are angled relative to one another to provide three liquid streams 6 that are spaced apart along the wiper blade. The distance between the outermost contact points for the streams 6 is preferably at least 50 and more desirably at least 70% of the length of the wiper blade 3.

If desired the side parts 36, 37 of the nozzle means 5 may be lowered to a point between the position illustrated in Figure 9 and the windscreen 1 to reduce or minimise the tendency for the streams 6 to be broken up or deflected before they contact the desired windscreen surface area.

Claims

1. A windscreen cleaning system for a motor vehicle, said windscreen cleaning system including wiper means having at least one wiper arm and at least one flexible wiper blade pivotally connected to the or each said wiper arm via a harness adapted to apply windscreen contacting forces to said wiper blade at spaced positions along the wiper blade, said windscreen cleaning system further including washing liquid supply means co-operable with said wiper means having a washing liquid nozzle means carried by said wiper means and washing liquid delivery means for delivering pressurised washing liquid to said washing liquid nozzle means whereby, in use of the washing liquid supply means, one or more pressurised washing liquid streams are applied to a windscreen of the motor vehicle, said washing liquid supply means further including control means for alternating the direction of the washing liquid streams such that washing liquid is only directed forwardly of a said wiper blade onto said windscreen of the motor vehicle regardless of direction of movement of the wiper blade, said washing liquid stream or streams having a velocity sufficient for the washing liquid to strike the windscreen of the motor vehicle when the motor vehicle is moving at a maximum legally allowed speed of the vehicle.

2. A windscreen cleaning system according to Claim 1, wherein the washing liquid nozzle means includes at least two spray nozzle delivery outlets directed towards the vehicle windscreen on each side of the wiper blade.

3. A windscreen cleaning system according to Claim 3, wherein three said spray nozzle delivery outlets are directed towards the vehicle windscreen on each side of the wiper blade.

4. A windscreen cleaning system according to Claim 2 or Claim 3, wherein washing liquid streams delivered by each said washing liquid nozzle delivery outlets form an angle of no more than 450 to a vertical plane at 900 to the windscreen at a point of contact of the stream with the windscreen.

5. A windscreen cleaning system according to Claim 4, wherein said angle is less than 30 .

6. A windscreen cleaning system according to Claim 2 or Claim 3, wherein the windscreen contact points for the two outermost liquid streams supplied by said nozzle delivery outlets are separated by a distance at least equal to 50% of the length of the wiper blade.

7. A windscreen cleaning system according to Claim 2 or Claim 3, wherein the washing liquid nozzle means is carried by the or each said wiper arm.

8. A windscreen cleaning system according to Claim 7 wherein the nozzle delivery outlets are located no further in a perpendicular direction from the windscreen than the wiper arm.

9. A windscreen cleaning system according to Claim 8, wherein the nozzle delivery outlets are located between the wiper arm and the windscreen.

10. A windscreen cleaning system according to Claim 1, wherein the washing liquid nozzle means is mounted on the wiper blade.

11. A windscreen cleaning system substantially as herein described with reference to the accompanying drawings.