WO1998054036A1

WO1998054036A1 - Windshield wiper

Info

Publication number: WO1998054036A1
Application number: PCT/SE1997/000948
Authority: WO
Inventors: Björn JOHANNESSON
Original assignee: Statens Järnvägar
Priority date: 1995-11-30
Filing date: 1997-05-30
Publication date: 1998-12-03
Also published as: SE505404C2; AU3560997A; SE9504293L; SE9504293D0

Abstract

Windshield wiper comprising a symmetrically formed body profile (1), onto which is arranged, two substantially parallel wiper blades (4), a scraping element (11) placed between the wiper blades (4), and a bellow (10) likewise placed between the wiper blades (4), which is expandable by air or liquid and arranged to co-operate with the scraping element (11). The body profile (1) is provided with a manoeuvring track (8), in which the scraping element (11) mounted on a wiper rail (9) is slidably movable through the expansion of the bellows (10).

Description

Windshield wiper

TECHNICAL FIELD

The present invention relates to windshield wipers, and particularly to such windshield wipers that are driven by a wiper motor in a to-and-fro motion across the windshield and that are provided with a pair of wiper blades and a device for scraping the windshield clean from insects and the like.

BACKGROUND OF THE INVENTION

Most vehicles which are equipped with a windshield are also equipped with a windshield wiper, the main purpose of which is to keep the windshield clear from water. The water removing effect is achieved by a wiper blade, preferably of rubber, affix- ed to a holder, which sweeps across the windshield in a to-and-fro motion. The effect can be improved by doubling the number of wiper blades on each holder. Furthermore, these vehicles, and in some cases also their windshield wipers, are provided with a washer fluid delivery system for cleaning the windshield when required. The washer fluid delivery system makes it possible to spray detergent directly onto the windshield for dissolving more severe dirt.

From the international patent application PCT/US88/01621 (WO 88/08797) is previously known a windshield wiper provided with a pair of wiper blades and a scraping element placed between the wiper blades, which scraping element is arranged to be moved out between the wiper blades when the windshield is to be scraped. In one embodiment in the mentioned patent application, the scraping element is adapted to be moved out against the windshield by an elastic device which is expanded by means of washing fluid or compressed air and which pushes the scraping element out against the windshield. Return to inoperative position is effected in that the device, due to its elasticity, retains its original position when the pressure ceases.

This construction has the disadvantage that the elasticity of the expanding device is decreased relatively fast, whereby the function of the to-and-fro motion is impaired. It is also difficult to achieve a uniform to-and-fro motion along the entire length of the wiper. Furthermore, the mentioned construction is provided with a pair of wiper blades made in one piece, i.e. a relatively complicated construction, which blades are provided with gripping edges to fit a holder manufactured specially for the blades.

Furthermore, this known construction is provided with a scraping surface which is fitted directly onto the elastic device, whereby it becomes considerably more difficult to change the scraping surface.

A further embodiment in the mentioned document shows a scraping device secured to a pair of H-beams, which moves the scraping device between an inoperative and an operative position by the action of a cam member. This embodiment is relatively complicated, owing to that the cam member requires a specific driving means for its rotary motion.

OBJECT OF THE INVENTION

The object of the present invention is to provide a windshield wiper of the type shown in the document mentioned above, but which solves the problems connected with the previous device. The object is futhermore that it shall be easy to change the wiper blades one by one, against almost any type of standard blade and also against wiper blades sold by the metre. The present windshield wiper has also been designed considering the ability of the wiper blades to engage the windshield at relatively high vehicle speeds and in case of strongly curved windshields.

SUMMARY OF THE INVENTION

The windshield wiper comprises a specially designed holder in the form of an extruded aluminium profile. The holder is symmetrically formed and is adapted to receive two wiper blades, one on each side of the line of symmetry. Furthermore, a wiper rail is arranged in the holder for transverse movement in a space adapted in the holder. The transverse movement of the wiper rail is achieved by pressurising an elastic bellow, preferably of rubber, with air or liquid. The transverse movement causes a scraping element in the form of a sponge, which is attached to the wiper rail, to be pushed out against the windshield to clean the same.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view, showing a windshield wiper in accordance with the invention. Figure 2 is a cross section on the line A-A of figure 1 , showing the windshield wiper in the position for normal wiping of rain. Figure 3 is a cross section corresponding to figure 2, but showing the windshield wiper in the position for scraping.

DESCRIPTION OF THE INVENTION

Figure 1 shows a windshield wiper comprising a body profile 1 , which extends along the entire length of the wiper. The body profile 1 is attached to a motor-driven wiper arm 2 via a holder 3, which is displaceably adapted to the body profile 1. The holder 3 is secured to the body profile 1 at an optional position along the body profile 1 by means of a locking device (not shown). Rubber wiper blades 4 for wiping of rain are attached to the body profile 1. These wiper blades 4 are slidably inserted into two recesses 5a,5b formed in the body profile 1 , see figure 2, and are secured from sliding in each recess by a locking clamp. The locking clamp has two pins facing each other, which are hooked from either side of the body profile through apertures in the body profile and into transverse grooves, designed for this purpose in the wiper blades. As will be seen from figure 2, the wiper blades 4 are each provided with a guide rail 7a,7b for stiffening the blades and thereby facilitating the handling of the blades when they are changed.

The body profile 1 has a symmetrical cross section, see figure 2, and its recesses 5a, 5b for the wiper blades 4 are arranged on either side of the line of symmetry, with the openings of the recesses facing the windshield. Consequently, the windshield wiper is provided with two wiper blades 4 for wiping of rain. The body profile 1 is further provided with a U-shaped symmetrically placed manoeuvring track 8, which also has its opening facing the windshield. The manoeuvring track receives a wiper rail 9, which is transversally slidable in the track. In the embodiment shown, the wiper rail 9 consists of a pair of H-beams having a web in parallel with the windshield. A manoeuvring bellows 10 is mounted between the web of the H-beams and the bottom of the manoeuvring track, and on the other side of the web, the side facing the windshield, a scraping element 11 is mounted. The manoeuvring bellows 0 is arranged to expand by being pressurised by air or liquid. The manoeuvring bellows 10 is formed as an elongate hollow rubber beam, which on the side facing the web of the wiper rail (H-beams) is provided with a pressing shoulder 12. The pressing shoulder 12 is arranged along the entire length of the bellows 10, and at the expansion of the bellows the pressing shoulder 12 forces the wiper rail 9 towards the windshield, whereby the space between the bottom of the manoeuvring track and the web of the wiper rail increases. This movement causes the scraping element 11 , which is attached to the other side of the web of the wiper rail, to be pressed against the windshield, thereby lifting the body profile 1 with its wiper blades 4 away from the windshield, see figure 3, to a position for insect cleaning. During this process, the flanges of the wiper rail (H-beams) are functioning as sliding surfaces against the walls of the manoeuvring track. The flanges are formed with such dimensions that a good guidance in the manoeuvring track is achieved. The wiper rail 9 may also be formed as a U-shaped beam, where the side of the web facing the windshield is provided with a scraping element in the way previously described. In this case the flanges of the U-shaped beam are directed towards the manoeuvring bellows and are functioning, in the same way as the flanges of the H- beams, as guidance against the walls of the manoeuvring track.

The manoeuvring bellows 10 is made of crude rubber or of an elastic polymer, and is pressurised via a, not shown, hose. The manoeuvring bellows 10 extends substantially along the entire length of the body profile. In the embodiment shown in figure 2 and 3, a dowel 13 of elastic material is attached to the body profile 1 and the wiper rail 9 in such a way that a spring force, acting against the expansion of the manoeuvring bellows, will bring back the wiper rail 9 and thereby the scraping element 11 towards the body profile 1 , when the pressure in the manoeuvring bellows 10 decreases. As will be seen from the figures, the two flanges of the wiper rail 9 determine the stop position for the wiper rail at its inner position, i.e. the position for wiping of rain. An elastic dowel 13 is suitably arranged at each end of the body profile 1.

The manoeuvring bellows 10 is in a not shown embodiment provided with a number of nozzles, through which washing fluid or the like can flow out at the expansion of the bellows. In this embodiment, also the wiper rail 9 is provided with perforations or nozzles, so that fluid will trickle into the scraping element 11 and thereafter get onto the windshield.

Figure 2 shows the position of the wiper during wiping of water. In this position, the manoeuvring bellows 10 is not pressurised, and the bellows is compressed owing to that the elastic dowels 13 are pulling the wiper rail 9 (H-beams) towards the bottom of the U-shaped manoeuvring track. Figure 3 shows the position of the wiper during scraping. In this position, the manoeuvring bellows 10 is pressurised, and the pressing shoulder 12 of the bellows has pushed out the wiper rail 9 with its scraping element 11 against the action of the elastic dowels 13. It will also be seen from figure 3, that the wiper blades 4 are raised from the windshield in the position for scraping.

The scraping element 11 is made of a relatively hard sponge, which can scrape away insects and the like, but which is soft enough not to damage the windshield. If the bellows is expanded by means of washing fluid or some other detergent, perforations are arranged in both the bellows and the wiper rail, so that the scraping element will be soaked with fluid.

The body profile 1 is further provided with two guides 14, facing each other, for keeping the holder 3 in a suitable position. Furthermore, the body profile 1 is provided with two symmetrically arranged pressure wings 15, outwardly inclined from the windshield, which help to press the windshield wiper against the windshield at high speeds.

If the windshield wiper is used on strongly curved surfaces, the wiper rail 9 is suitably articulately shaped, with one or more joints, to enable the wiper rail 9 to bend into engagement with the windshield along the whole length of the wiper.

Claims

Claims:

1. Windshield wiper comprising a symmetrically formed body profile (1), onto which is arranged, two substantially parallel wiper blades (4), a scraping element (11) placed between the wiper blades (4), and a bellow (10) likewise placed between the wiper blades (4), which is expandable by air or liquid and arranged to cooperate with the scraping element (11), characterized in that the body profile (1) is provided with a manoeuvring track (8), in which the scraping element (11) mounted on a wiper rail (9) is slidably movable through the expansion of the bellows (10).

2. Windshield wiper according to claim 1 , characterized in that the wiper rail (9) is provided with flanges functioning as sliding surfaces against the walls of the manoeuvring track (8).

3. Windshield wiper according to claim 2, characterized in that the wiper rail (9) comprises a web extending between the flanges, that the bellows (10) is arranged in a space between the web and the bottom of the manoeuvring track, and that the scraping element is attached to the web on the side of the web facing the windshield.

4. Windshield wiper according to one of claim 1-3, characterized in that at least one elastic element (13) is arranged to action between the body profile (1) and the wiper rail (9), such that a spring force acting against the expansion of the bellows will bring back the wiper rail (9) towards the bottom of the manoeuvring track, when the pressure in the manoeuvring bellows (10) decreases.

5. Windshield wiper according to claim 4, characterized in that the elastic element (13) is constituted by a dowel of elastic material.

6. Windshield wiper according to one of claim 1-5, characterized in that the wiper rail (9) is articulately shaped, with one or more joints, to make it easier for the wiper rail (9) to bend into engagement with the windshield

7. Windshield wiper according to one of claim 1-6, characterized in that the body profile (1) is provided with two pressure wings (15), outwardly inclined from the windshield.

8. Windshield wiper according to one of claim 1-7, characterized in that the body profile (1) is provided with two guides (14), facing each other, adapted for the holder (3) of the wiper.

9. Windshield wiper according to one of claim 1-8, characterized in that a pressing shoulder (12) is arranged along the entire length of the bellows (10), which at the expansion of the bellows (10) presses the wiper rail (9) towards the windshield.

10. Windshield wiper according to one of claim 1-9, characterized in that the bellows (10) is provided with a number of nozzles, through which washing fluid or the like can trickle onto the windshield via the wiper rail (9) and the scraping element (11).