GB2278270A

GB2278270A - Windscreen wiper blade with airfoil

Info

Publication number: GB2278270A
Application number: GB9310689A
Authority: GB
Inventors: Roger William Baker
Original assignee: Trico Ltd
Current assignee: Trico Ltd
Priority date: 1993-05-24
Filing date: 1993-05-24
Publication date: 1994-11-30
Anticipated expiration: 2013-05-24
Also published as: GB9310689D0; GB2278270B

Abstract

A windscreen wiper blade with at least a primary yoke and two secondary yokes has an airfoil vane (3) camped by the primary yoke (5) which comprises a slot (35) in which a longitudinal edge of the primary yoke sits and retention means which may comprise projections (39, 41, 43, 45) on the airfoil vane adapted to snap fit in apertures (47) in the yoke. <IMAGE>

Description

WINDSCREEN WIPER BLADE WITH AIRFOIL This invention relates to a windscreen wiper blade with an airfoil.

In the field of windscreen wipers, with the advent of vehicles travelling at relatively high speeds, problems have arisen as a result of the air passing over the windscreen wiper blades has caused these to be lifted from the windscreen with a consequent loss of wipe.

To counteract this, many proposals have been made ranging from specially shaped wiper blades or arms to the provision of a variable spring pressure enabling the windscreen wiper blade to pressed with greater pressure on to the windscreen at high speeds while reducing the pressure at low speeds.

One of the commonest methods of combating so called "wind lift" has been the provision of airfoils or vanes, fitted to the windscreen wiper blade and being acted on by the air passing over the car to provide a downward pressure on the windscreen wiper blade. However, while this solution has proved successful in combating the technical problem, difficulties have arisen in respect of connecting these airfoils to the blade in an economic and aesthetically pleasing manner.

The present invention seeks to provide an airfoil windscreen wiper blade in which some or all of the above disadvantages are reduced or substantially obviated.

According too the invention, there is provided an airfoil windscreen wiper blade comprising at least one primary yoke or lever, at least two secondary yokes or levers pivotally connected to the primary yoke or lever, a blade rubber carried by the secondary yokes or levers and an airfoil vane carried by the primary yoke, the airfoil vane having a slot in which a longitudinal edge of the primary yoke or lever sits and retention means to enable the airfoil vane to be maintained on the primary yoke or lever.

Preferably the retention means comprises a snap fitting element associated with a complimentary element on the main yoke or lever. The snap fitting element may comprise one or more projections on the airfoil vane which cooperate with one or more corresponding apertures in the main yoke or lever.

The arrangement may be such that when the slot in the airfoil vane is pushed over the edge of the main yoke or lever, the projection(s) on the airfoil vane automatically enter the aperture(s) in the main yoke or lever. To this end, the projection(s) may be chamfered.

Suitably the yokes or levers of the blade are of a suitable metal while the airfoil vane is if plastics material.

The invention will now be described, in greater detail, by way of example, with reference to the drawings in which: Figure 1 is a front view of one form of windscreen wiper blade in accordance with the invention; Figure 2 a plan view of the windscreen wiper blade of figure 1; Figure 3 is a rear view of the windscreen wiper blade of figure 1; Figure 4 is a rear view of an airfoil vane as shown in front view in figure 1; Figure 5 is a sectional view taken along the line V-V of figure 4, and Figure 6 is a sectional view, similar to that of figure 5 but taken on the line VI-VI of figure 4.

Referring to the drawings, there is shown a windscreen wiper blade 1 having a usual construction with an airfoil vane 3 attached thereto in accordance with the invention. The blade 1 shown comprises a primary yoke or lever 5 carrying at its ends 7 a respective secondary yoke or lever 9. These yokes or levers 9 are pivoted to main yoke or lever 5 in their central regions and are provide, at their inner ends, with a tertiary yoke or lever 15 and have claws 11 at their outer ends. Both ends of the tertiary yokes have claws 17 at their ends. The arrangement of the secondary and tertiary yokes may vary as is well known and form no part of the present invention. It is, however, with the primary yoke that we are concerned.

The primary yoke or lever is of generally inverted channel shape having a base portion 23 and two depending side portions 25 and 27. As can be seen, the airfoil vane 3 is attached to the depending side portion 27 of the primary yoke 5 and extends both longitudinally and below the yoke 5.

The construction of the airfoil vane 3 can be best seen from figures 4 to 6 which show respectively a rear view and two sectional views of the vane. the front 31 of the vane 5 is plain and can be seen particularly in figures 1 and 2. The airfoil vane 3 is suitably moulded from plastics material and comprises an elongate member having a plain front side 31 and a rear side 33 provided with means for attachment of the vane to the depending side portion 27 of the primary yoke.

To this end the vane 3 is provided with a pair of slots or pockets 35, the shape of which can best be seen in cross section in figure 5. These slots or pockets 35 are adapted to receive the the side portion 27 of the primary yoke 5 so as to locate the vane 3 thereon. Retention of the vane 3 in this position is achieved by means of four projections 39, 41, 43 and 45 which cooperate with apertures 47 formed in the side portion 27 of the primary yoke or lever 5. The shape of one of these projections (41) is shown in section in figure 6 and is of sawtooth shape with the apex of the tooth at the lowermost end. The method of assembly will be described hereafter.

Since the vane 3 is made from plastics material, but must remain substantially rigid in use, it has various stiffening features.

Firstly there is the thickening of the vane 3 at 53 where the side wall 55 of the slots or pockets 35 meet the main body of the vane 3. Secondly, there is a rib 57 which extends between the thickenings 53 of the slots or pockets 35 and also extends outwardly from these thickenings 53 towards the longitudinal extremities of the vane 3. Thirdly, the lower and end edges of the vane are provided with a rib construction comprising inner and outer ribs 59 and 61 respectively separated by a groove 63.

From the above it will be appreciated that the lower part of the vane 3 is longitudinally relatively rigid while allowing, particularly in the upper part of the vane 3 where it lies alongside the side portion 27 of the primary yoke to have a certain resilience in the transverse sense to enable assembly.

Since, as can be seen in figures 1 to 3, the windscreen wiper blade 1 is usually connected to a windscreen wiper arm (not shown) by a connector 73 located on a rivet or pivot pin 75 extending transversely of the primary yoke or lever 5, the vane 3 may be recessed at 77 to enable the rivet head or the like to be accommodated.

Assembly of the vane 3 to the blade 1 will now be described: The windscreen wiper blade is firstly assembled as a standard blade in known fashion, the only departure from the standard form being the four apertures 47 which are formed in the primary yoke or lever 5 during initial forming thereof. The mould vane 3 is offered up to the appropriate side portion 27 of the primary yoke so that the side portion 27 slides into the slots or pockets 35. This operation is assisted by the inclined inner edge 65 of the side wall 67 of the slots or pockets.

As the vane 3 is pushed home on the side portion 27 of the primary yoke or lever, the lower edge 69 of the side portion 27 will engage the bottom 71 of the slot or pocket 35 and, at this time, the projections 39, 41, 43 and 45 will become in register with the respective apertures 47 in the primary yoke or lever 5.

Because of the resilience of the vane 3 and the shape of the projections 39, 41, 43, these projections will slip over the side portion 27 of the primary yoke or lever 5 and will, when in register with the apertures 47, snap into these apertures. The shape of the projections 39, 41, 43 will ensure that they cannot slip out of the apertures 47 by any attempt to pull the vane 3 off the primary yoke or lever 5 and thus the vane 3 will be held securely in place.

It will be appreciated that various modifications can be made to the above described embodiment without departing from the scope of the invention. For example, if desired, the pair of slots or pockets 35 could be replaced by a single slot or pocket preferably extending longitudinally to a greater extent than either of the existing slots or pockets 35. Alternatively, three or more pockets could be used. The number of projections 39, 41, 43 could be increased or decreased as desired.

Claims

1. A windscreen wiper blade comprising at least one primary yoke or lever, at least two secondary yokes or levers pivotally connected to the primary yoke or lever, a blade rubber carried by the secondary yokes or levers and an airfoil vane carried by the primary yoke, the airfoil vane having a slot in which a longitudinal edge of the primary yoke or lever sits and retention means to enable the airfoil vane to be maintained on the primary yoke or lever.

2. A windscreen wiper blade as claimed in claim 1, wherein the retention means comprises a snap fitting element associated with a complimentary element on the main yoke or lever.

3. A windscreen wiper blade as claimed in claim 2, wherein the snap fitting element comprises one or more projections on the airfoil vane which cooperate with one or more corresponding apertures in the main yoke or lever.

4. A windscreen wiper blade as claimed in claim 3, wherein the arrangement is such that when the slot in the airfoil vane is pushed over the edge of the main yoke or lever, the projection(s) on the airfoil vane automatically enter the aperture(s) in the main yoke or lever.

5. A windscreen wiper blade as claimed in claim 4, wherein the projection(s) are chamfered.

6. A windscreen wiper blade as claimed in any preceding claim, wherein the yokes or levers of the blade are made from metal while the airfoil vane is made of plastics material.

7. A windscreen wiper blade with an airfoil substantially as described herein with reference to the drawings.