GB2140287A

GB2140287A - Anti-windlift wiper arm and blade assemblies

Info

Publication number: GB2140287A
Application number: GB08412923A
Authority: GB
Inventors: Graham Durtnal
Original assignee: Trico Ltd
Current assignee: Trico Ltd
Priority date: 1983-05-24
Filing date: 1984-05-21
Publication date: 1984-11-28
Also published as: GB8412923D0; GB2140287B

Abstract

A wiper arm and blade assembly 10, in which the wiper arm 12 comprises an elongate arm piece 16 having an inner end portion carried by a retainer 18 and having an outer termination connected at 20 to a central portion of the blade 14 for relative pivotal movement, and the blade 14 comprises at least one upper surface formed or secured thereon and extending longitudinally of the blade which surface in use has an anti-windlift effect on the blade, such as anti-windlift vanes 28, is characterised in that between the retainer and the outer termination of the arm piece a length 32 of the arm piece lying adjacent to one of said vanes 28 on the blade presents an under surface 36 which is bounded by front and rear longitudinal edges of which, in use, the rear longitudinal edge 38 with regard to incident air flow is the higher from a windscreen, the wiper arm being mounted either directly above the blade (as shown) or by the side of the blade. <IMAGE>

Description

SPECIFICATION Anti-windlift wiper arm and blade assem blies The present invention is concerned with the anti-windlift capabilities of wiper arm and blade assemblies.

In a wiper arm and blade assembly accord ing to the present invention, the wiper arm comprises an elongate arm piece having an inner end portion carried by a retainer and having an outer termination connected to a central portion of the blade for relative pivotal movement, and the blade comprises at least one upper surface formed or secured thereon and extending longitudinally of the blade which surface in use has an anti-windlift effect on the blade, characterised in that between the retainer and the outer termination of the arm piece a length of the arm piece lying adjacent to the said surface on the blade presents an under surface which is bounded by front and rear longitudinal edges of which, in use, the rear longitudinal edge with regard to incident air flow is the higher from a windscreen.

In one embodiment, the wiper arm is mounted directly above the blade (top mounting). The said upper surface on the blade is formed on a main yoke, or on a pair of pivotally connected cantilevers, which is shaped to present a pair of anti-windlift vanes separated from one another by the pivotal connection of the upper surface on the blade to the outer termination of the arm piece.

Each of the vanes has a rear longitudinal edge which is higher from the windscreen than its front longitudinal edge. Without the present invention, the effectiveness of the anti-windlift vanes on the blade tends to be inhibited by the presence of the arm piece upstream in the air flow. With the present invention, however, it is found that the blade can be maintained in contact with the windscreen at some 1 Okph higher than without the application of the invention at vehicle speeds of 160 kph or so.

In another embodiment, which brings a comparable improvement, the wiper arm and the blade extend side by side (side mounting).

More generally, the anti-windlift vanes could be replaced by some other type of antiwindlift device or devices, which could be separate from but attachable to the blade as 3 whole, or to its main yoke or individual primary levers, rather than being formed integrally with those parts of the blade.

The under surface of the arm piece may be formed on a bar of rectangular cross-section whose middle section is inclined by twisting with respect to the inner portion and the outer termination.

Wiper arm and blade assemblies, according to the present invention, will now be described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a side view of a first wiper arm and blade assembly; Figure 2 is an enlarged cross-sectional view taken along the line Il-Il of Fig. 1; Figure 3 is a side view of a second wiper arm and blade assembly; Figure 4 is an enlarged cross-sectional view taken along the line IV-IV of Fig. 3; and Figure 5 is a plan view of the second wiper arm and blade assembly.

It will be clear to the reader that the assembly shown in Figs. 1 and 2 is of the top mounting kind whereas the assembly shown in Figs. 3 to 5 is of the side mounting kind.

In many other respects, however, the two assemblies shown in the accompanying drawings are similar. It will thus be necessary merely to describe in detail the assembly shown in Figs. 1 and 2 and state that the same reference numerals with suffix a have been used for the assemly shown in Figs. 3 to 5.

An assembly 10 includes a wiper arm 12 and a blade 14 of the form we used for testing a 760 Volvo (1982 model) and a 360 Volvo (1983 model).

The wiper arm 12 includes an elongate bar 16 of rectangular cross-section having an inner end portion carried by a retainer 18 and having an outer termination pivoted at 20 to the blade 14. The retainer 18 can be of a standard construction, in which a spring provides a loading of 670-680 gr. to the pivot at 20 on the blade against a windscreen, and the pivot at 20 can utilise a standard construction of connector. The outer termination is inclined by bending downwardly in Fig. 1 and to one side in Fig. 5, so that the longitudinal centre line of the outer termination is not aligned with the longitudinal centre line of the remainder of the bar 16. The blade 14 includes a squeegee 22, whose length is 500 mm, carried by a backing strip 24 and 5-yoke harness 26. The main yoke is formed with two longitudinally spaced anti-windlift vanes 28, extending longitudinally of the blade 14, one on each side of the pivot at 20, the rear edges 30 of the vanes 28 being higher than their front edges.

A middle section 32 of the bar 16 has equal and opposite twists 34 at each end thereof so that an under surface 36 of the middle section 32 is inclined at an angle of 27+ to the horizontal, its rear edge 38 being higher than its front edge.

The middle section 32a of the wiper arm 12a shown in Fig. 5 may lie at an angle of 10 to the blade 14a.

Although the positions, dimensions and angles are preferably as shown in the accompanying drawings, changes in the relative positions, dimensions and angles are possible.

Claims

1. A wiper arm and blade assembly, in which the wiper arm comprises an elongate arm piece having an inner end portion carried by a retainer and having an outer termination connected to a central portion of the blade for relative pivotal movement, and the blade comprises at least one upper surface formed or secured thereon and extending longitudinally of the blade which surface in use has an antiwindlift effect on the blade, characterised in that between the retainer and the outer termination of the arm piece a length of the arm piece lying adjacent to the said surface on the blade presents an under surface which is bounded by front and rear longitudinal edges of which, in use, the rear longitudinal edge with regard to incident air flow is the higher from a windscreen.

2. A wiper arm and blade assembly according to claim 1, in which the said upper surface on the blade is formed on a main yoke, or on a pair of pivotally connected cantilevers, which is shaped to present a pair of anti-windlift vanes separated from one another by the pivotal connection of the upper surface on the blade to the outer termination of the arm piece.

3. A wiper arm and blade assembly according to claim 1 or claim 2, in which the under surface of the arm piece is formed on a bar of rectangular cross-section whose middle section is inclined by twisting with respect to the inner portion and the outer termination.

4. A wiper arm and blade assembly substantially as hereinbefore described with reference to Figs. 1 and 2, or Figs. 3 to 5, of the accompanying drawings.