GB2190834A

GB2190834A - Windscreen wiper blade

Info

Publication number: GB2190834A
Application number: GB08710649A
Authority: GB
Inventors: Peter Mower; Graham Durtnal
Original assignee: Trico Ltd
Current assignee: Trico Ltd
Priority date: 1986-05-06
Filing date: 1987-05-06
Publication date: 1987-12-02
Anticipated expiration: 2007-05-06
Also published as: GB8611019D0; GB2190834B; GB8710649D0

Abstract

A windscreen wiper blade 1 comprising a main yoke 3 and secondary yokes 5 supporting rubber 2 is characterised in that the main yoke is provided with an air-deflecting vane 16 which extends beyond the points at which the ends of the main yoke are pivotably connected to the secondary yokes. <IMAGE>

Description

SPECIFICATION Bladeforwindscreen wiper This invention relates to a blade for a windscreen wiper.

With the advent of high speed vehicles, it is necessaryto take into account the airflow over the vehicle so asto avoid significantwind resistance and with it poor fuel economy.

The higher speeds ofthevehicles coupled with the aerodynamic shape used provides problems for windscreen wipers due to the airflow causing the blades to be lifted, at least parially,from the windscreen impairing the visibility of the driver of the vehicle in wet conditions.

Many proposals have been made for overcoming these problems, in particular the provision of a number of differenttypes of vane attached to various parts ofthe blade orthe windscreen wiper arm and the provision of slotted members used in the blade harness to reduce the effect of wind resistance of the windscreen wiper blade.

The present invention seeks to provide a windscreen wiper blade having an improved wiping performance at high vehicle speeds.

According to a first aspect ofthe invention, there is provided a blade for a windscreen wiper comprising a main yoke having connection means for connection to a windscreen wiper arm and being articulated at its ends to a secondary yoke or lever, wherein the main yoke is provided on the side ofthe blade intended to face the air flow with a depending vane which extends along the length of the main yoke and extends beyond the articulation points of the main yoke to the secondary yoke or lever.

Further according to this aspect ofthe invention, there is provided a blade for a windscreen wiper comprising a main yoke having connection means for connection to a windscreen wiper arm and being articulated at its ends to a secondary yoke, wherein the main yoke is of channel shaped section at its ends and at the connection means for the windscreen wiper arm, the channel section parts being connected together by means of a connecting side wall in the form of a continuation of that side wall ofthe channel section intended to face into the airflow, at least part of the base and the other side wall of the channel being omitted, the connecting side wall being formed as a downwardly extending vane which extends thefull length ofthe main yoke between the articulation points and additionally extends beyond these articulation points.

Preferably the vane extends almost to the end of the blade.

According to a second aspect ofthe invention, there is provided a blade for a windscreen wiper comprising a main yoke having connection means for connection to a windscreen wiper arm and being articulated at its ends to a secondary yoke or lever, wherein the primary yoke is of substantially channel shaped section at its ends and at the connection meansforthe windscreen wiper arm, the channel section parts being connected together by means of a continuation of one channel side, at least part of the base and the other side of the channel on that side of the blade intendedtoface away from the airflow direction being omitted.

The connecting sidewalls of the channel section may be cut back beyond the upper edge thereof so that the connection meansforthewiperarmandtheends carrying the articulation points stand slightly proud of the remainder of the main yoke. Alternatively, a part of the base of the channel section may be retained atthe connecting side walls, so that a lip is formed atthe upper edge of the connecting side walls. In this event, the connecting part will form an inverted "L" shaped section, the foot of the "L" being of a dimension less than the width of the base ofthe channel section.

The invention will now be described in greater detail, by way of example, with reference to the drawings, in which: Figure lisa perspectiveviewofoneform of windscreen wiper blade in accordance with the invention taken from the side of the blade away from the intended airflow: Figure 2 is a perspective view similarto figure 1 but showing the other side of the windscreen wiper blade, and Figure 3 is a plan viewofthewindscreen wiper blade shown in figures 1 and 2.

Referring to the drawings, there is shown a windscreen wiper blade 1 comprising a blade rubber 2 which is carried by a harness. This harness comprises a main yoke 3 articulated at its ends 4 to a secondary lever which in turn is articulated, at its inner end, to a subsidiary yoke 6. The blade rubber 2 is held by a claw arrangement 8 provided on the outer ends of the secondary lever 5 and on both ends of the subsidiary yoke 6. The specific construction of the secondary lever 5, the subsidiary yoke 6 and the blade rubber2 form no part ofthe invention and can be of any suitable known form.

The primary yoke 3 has a central portion 9 which is of substantially channel section and is provided with an opening 10 in the base for receiving a connector for thetermination of a windscreen wiper arm. To this end, the walls ofthe channel at this point are apertured at 11 to receive the pivot pin (not shown).

At each end 4 of the main yoke 3, there is an articulation portion 12, also of channel section. These channel section portions 12 are provided, in the form shown,with rivets ortrunnion connections 14 acting as pivot pins. The three channel shaped portions 8 and 12 are connected together by a connecting portion 15 in the form of a downwardly extending vane 16 which in effectforms a continuation of the side wall ofthe channel so that, in the region of these connecting portions l5,thebaseandtheothersidewallofthe channel are omitted.It will be appreciated that becausetheside walls ofthe connecting portions 15 are in theform of a vane, they are not, in general, 'parallel to the side walls of the channel sections of the articulation portions 12 and the connection means 8. The drawing(s) originally filed was (were) informal and the print here reproduced is taken from a later filed formal copy.

As can be particularly seen from figures 2 and 3, the downwardly extending vane 16, which also forms the connecting parts ofthe main yoke, extends past what would normally be the end ofthe main yoke 3 i.e. the articulation points 12, and extendstowardsthe ends of the blade, thus forming a downwardly extending vane which is approaching or ofsubstantiallythe same length as the blade. As can also be seen, particularly in connection with figure 2, not only is the baseandothersidewalloftheconnectingportion 15 omitted, but part of the side wall of the connecting portion 15 is cut back slightly at 17 so that the articulation points 12 and the blade to arm connecting means 8 stand somewhat proud of the remainder of the main yoke 3.As can also be seen from figure 2, the downwardly extending vane 16 not only extends downwardly but is curved outwardly at the same time to provide a suitable aerodynamic profile. The exact curvature and dimensions of the downwardly extending vane 16 will depend on various considerations such as the type of windscreen with which the wiper is to be used and the airflow pattern which is created by the vehicle itself.

twill be appreciated that, in use,the windscreen wiper blade will be installed with the vane facing the oncoming airflow. Because of the nature ofthe air flow on vehicles and the wiping pattern adopted by the windscreen wipers, it is not usually necessary to provide the type of blade in accordance with the invention on both arms of a dual windscreen wiper system although this may be done for aesthetic reasons. With a vehicle fitted for right hand drive as is normal in this country, the blade would befitted on the driver's side.

It will be appreciated that various modifications may be made to the above described embodimentwithout departing from the scope of the invention. Firstly, it will be understoodthattheformation ofthe main yoke with the effectively cut back portions between the articulation points 12 and the blade to arm connection 8 may be used on its own without the use ofthe downwardly extending vane 16. In these circumstances, the connecting portions 15would normally be a precise continuation of one side wall of the channel sections of the articulation points 12 and the arm to blade connection 8 so that the connecting portions 15 would be parallel to the side walls of the channel sections.

Alternatively, the downwardly extending vane formation may also be used on its own withoutthe provision ofthe cut back portions ofthe connecting portions 15, it being understood that while this is so, the best results will be obtained by a combination of the two. Additionally, the length and shape of the vane could be varied significantly.

The connection portions 15 need not be cut back below the height of the articulation portions 12 and the connecting means 9forthe arm to blade connection sothattheupperedgeofthesidewallsofthemain yoke could exhibit a straight line or a smooth curve.

Going further in this direction, it is possible to retain in theconnection portions 1 5 a certain amount of the base ofthe channel so that the connection portions 15 have an inverted "L" shaped section. The amount of the base portion remaining may vary considerably but it is envisaged that, in normal circumstances, not morethan half of the base portion would remain.

Tests which have been performed on a blade constructed in accordance with the invention, have indicated that such a blade can provide satisfactory wiping conditions at speeds in excess of 100 miles per hour.

Claims

1. A blade for a windscreen wiper comprising a main yoke having connection means for connection to a windscreen wiper arm and being articulated at its ends to a secondary yoke or lever, wherein the main yoke is provided on the side of the blade intended to face the airflow with a depending vane which extends along the length of the main yoke and extends beyond the articulation points of the main yoke to the secondary yoke or lever.

2. A blade for a windscreen wiper comprising a main yoke having connection means for connection to a windscreen wiper arm and being articulated at its ends to a secondary yoke, wherein the main yoke is of channel shaped section at its ends and at the connection means forthe windscreen wiper arm, the channel section parts being connected together by means of a connecting sidewall in the form of a continuation ofthat side wall ofthe channel section intended to face into the airflow, at least part of the base and the other side wall of the channel being omitted, the connecting side wall being formed as a downwardly extending vane which extendsthefull length ofthe main yoke between the articulation points and additionally extends beyond these articulation points.

3. A blade as claimed in claim 2, wherein the vane extends almost to the end of the blade.

4. A blade as claimed in claim 2 or 3 wherein the vane is curved outwardlyfrom the blade in the direction towards its lower edge.

5. A blade as claimed in claim 2,3 or4,whereinthe channel section parts have parallel sides at least in the region ofthe articulations.

6. A blade for a windscreen wiper comprising a main yoke having connection means for connection to a windscreen wiper arm and being articulated at its ends to a secondary yoke or lever, wherein the primary yoke is of substantially channel shaped section at its ends and at the connection means for the windscreen wiper arm, the channel section parts being connected together by means of a continuation of one channel side, at least part of the base and the other side ofthe channel on that side of the blade intended to face away from the airflow direction being omitted.

7. A blade as claimed in any one of claims 2 to 6, wherein the connecting side walls of the channel section are cut back beyond the upper edge thereof so that the connection means for the wiper arm and the ends carrying the articulation points stand slightly proud of the remainder of the main yoke.

8. A blade as claimed in any one of claims 2 to 6, wherein a part of the base of the channel section is retained at the connecting side walls, so that a lip is formed atthe upper edge of the connecting side walls.

9. A blade as claimed in claim 6, wherein the connecting partforms an inverted "L" shaped section, the foot of the "L" being of a dimension less than the width ofthe base ofthe channel section.

10. A bladefora windscreen wiper substantially as described herein with reference to the drawings.