GB1586179A

GB1586179A - Wiper harness assembly

Info

Publication number: GB1586179A
Application number: GB3433977A
Authority: GB
Original assignee: SWF Spezialfabrik fuer Autozubehoer Gustav Rau GmbH
Current assignee: SWF Auto Electric GmbH
Priority date: 1976-08-24
Filing date: 1977-08-16
Publication date: 1981-03-18
Also published as: FR2362740A1; DE2638010A1; FR2362740B1

Description

(54) WIPER HARNESS ASSEMBLY (71) We, SWF-SPEzIALFABRIK FUR AUTOZUBEHOR GUSTAV RAU G.m.b.h., a joint stock company organised under the Laws of Germany, of Stuttgarter Strasse119, 712 Bietigheim Bissingen, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a wiper harness assembly, particularly but not exclusively for holding a wiper blade rubber for use in cleaning extremely curved windows on automotive vehicles.

For cleaning extremely curved windscreens and in order to achieve a uniform pressure distribution, wiper harness assemblies comprise one main yoke and several articulated clawed yokes. In a known design at each end of the main yoke one two-armed clawed yoke is suspended like a beam balance and additionally a onearmed clawed yoke guiding the end of the wiper rubber is provided which is resiliently supported on the main yoke. The contact pressure thereby depends nearly exclusively on the rigidity of the pressure spring used.

In another known design the main yoke itself is directly supported on the wiper rubber by means of two claws. To the main yoke several one-armed clawed yokes are articulated, which are pressed towards the window to be cleaned by separate springs supported on the main yoke. The springs are designed such that the contact pressure is independent of the deflection during the wiping process on a curved window and remains constant.

Experience has shown that with such wiper harness assemblies and rubbers perfect cleaning of an extremely curved windscreen cannot be achieved. In the extremely curved area of the screen the contact pressure at the end of the wiper rubber is often too small, whereas in the flat area of the screen the contact pressure in the middle part of the wiper rubber is not sufficient, especially at high driving speeds.

According to the present invention there is provided a wiper harness assembly for distributing pressure to and holding a wiper blade rubber for cleaning an automobile window, the assembly comprising a main yoke and two secondary clawed yokes connected to one end of the main yoke so that they can pivot relative to the main yoke, one of the clawed yokes being one-armed and the other being two-armed, one of the clawed yokes being arranged for holding the end the wiper blade rubber, wherein pivotal motion of any one clawed yoke relative to the main yoke will alter the pressure applied to the rubber by the other clawed yoke in use of the assembly.

The invention thereby originates in the idea that the mostly unnecessarily high contact pressure at the end of the wiper rubber in the flat area of the window can be used for increasing the contact pressure in the middle area of the wiper rubber, whereas vice versa, when curved areas of the window are wiped, a clawed yoke associated with and guiding the middle area of the wiper rubber is adapted to the curvature of the window and this adaption effects an increase of the contact pressure at the end of the wiper rubber via a clawed yoke associated with the end of the rubber. By this redistribution of the contact pressure in the transition area from the flat to the curved area of the window the wiping effect is substantially improved.

One clawed yoke is preferably resiliently supported on the other clawed yoke. This construction is advantageously used if the clawed yokes are made of metal sheet. In wiper harness assemblies made of plastics material, however, according to a further advantageous development of the invention in one direction normal to the plane of the window to be cleaned one clawed yoke is shaped so as to be and is pivotably fast with the other clawed yoke.

The invention is described below by way of embodiments shown in the accompanying drawing, in which Fig. T is a part-sectioned side view of part of a wiper harness assembly with a wiper rubber which rests on a flat area of a win dow to be wiped and Fig. 2 is a side view of another embodiment in an unstressed condition.

In Fig. 1 a main yoke is designated by the numeral 10, a secondary two-armed clawed yoke by 11 and a secondary one-armed clawed yoke by 12, by means of which a wiper rubber 1 is supported. The yokes are made of metal sheet m a conventional manner and have a substantially U-shaped cross-section. Between the limbs, and at the end, of the main yoke 10 a pivot pin 14 is mounted to which both the two-armed clawed yoke 11 and the one-armed clawed yoke 12 are articulated. At the pivot pin 14 the yokes are nested within one another. A torsion spring 15 surrounds the pivot pin 14 and its ends 16 and 17 extend through recesses 18 and 19 and bear on the clawed yokes 11, 12. This torsion spring 15 is such that its ends press from above against back 20 and 21 of the clawed yokes 11 and 12.

Thus the torsion spring 15 tends to turn the one-armed clawed yoke 12 round the pivot pin 14 in the clockwise direction.

In the embodiment according to Fig. 2 all yokes are made of plastics material. The main yoke 10 is pivotally linked with the clawed yoke 11 by means of a socket and spigot as shown, and to the back of the clawed yoke 11 adjacent to the pivot the one-armed clawed yoke 12 is connected, the yokes 11 and 12 being formed in one piece.

The clawed yoke combination 11 and 12 is in one direction, normal to the plane of the window to be wiped, such that the yoke 12 is shaped so as to be resilient and so that in the unstressed condition the yoke combination has the configuration shown in Fig. 2. The three claws of the clawed yokes 11 and 12 are thereby located on one line 30, the radius of curvature of which is smaller than the smallest radius of curvature of the window to be wiped. As soon as the wiper rubber rests on the window to be wiped the one-armed clawed yoke 12 is thus subjected to forces in the counterclockwise direction and thereby resiliently stressed.

When the wiper rubber moves from a curved area of the window to a flat area the one-armed clawed yoke 12 is subjected to forces in the counterclockwise direction. In the embodiment according to Fig. 2 this motion is directly transmitted to the twoarmed clawed yoke 11 whereas in the embodiment according to Fig. 1 it is transmitted via the torsion spring 15. In both cases a pivot force acts on the two-armed clawed yoke, so that the contact pressure in the middle area of the wiper rubber, that is the portion of the rubber supported by the two-armed clawed yoke, in increased.

If, however, the wiper blade runs from the flat area of the window to the curved area the two-armed clawed yoke 11 and the yoke 12 are pivoted in the clockwise direction, the yoke 11 reacting first, because of the rigidity of the rubber, and its pivoting being either directly transmitted to the yoke 12 (Fig. 2) or via the torsion spring 15 (Fig. 1), so that the contact pressure at the end of the wiper rubber is accordingly increased.

The pivoting motion of one of the clawed yokes thus results in a change of the contact pressure exerted by the other clawed yoke, so that in the flat area of the window the contact pressure of the middle area of the wiper rubber is increased, whereas in the curved area of the window the contact pressure at the end of the wiper rubber is increased, that is, the contact pressure is distributed in accordance with the shape of the window.

In the drawings only two embodiments are shown which may be realized particularly easily in production. The yokes and also the torsion spring can be formed or supported otherwise. Especially it is also possible to arrange one claw of the twoarmed clawed yoke nearer to the pivot pin, that is, make one arm shorter. Finally also the main yoke 10 could have a claw, through which the wiper rubber is additionally supported. In the embodiment according to Fig.

2 the one-armed clawed yoke 12 could itself be rigid, and the transition area to the twoarmed clawed yoke could be formed as a resilient joint, which is easily possible due to appropriate dimensioning of the crosssection of the material. Secondary yokes 11 and 12 may be provided at one or both ends of main yoke 10, depending on the shape of the window to be wiped.

WHAT WE CLAIM IS: 1. Wiper harness assembly for distributing pressure to and holding a wiper blade rubber for cleaning an automobile window, the assembly comprising a main yoke and two secondary clawed yokes connected to one end of the main yoke so that they can pivot relative to the main yoke, one of the clawed yokes being one-armed and the other being two-armed, one of the clawed yokes being arranged for holding the end of the wiper blade rubber, wherein pivotal motion of any one clawed yoke relative to the main yoke will alter the pressure applied to the rubber by the other clawed yoke in use of the assembly.

2. Wiper harness assembly according to claim 1, wherein one clawed yoke is resiliently supported on the other clawed yoke.

3. Wiper harness assembly according to claim 1, wherein in one direction normal to the plane of the window to be cleaned one clawed yoke is shaped so as to be resilient and is pivotably fast with the other clawed yoke.

4. Wiper harness assembly according to claim 2 or 3, wherein the clawed yoke for

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

dow to be wiped and Fig. 2 is a side view of another embodiment in an unstressed condition.

In Fig. 1 a main yoke is designated by the numeral 10, a secondary two-armed clawed yoke by 11 and a secondary one-armed clawed yoke by 12, by means of which a wiper rubber 1 is supported. The yokes are made of metal sheet m a conventional manner and have a substantially U-shaped cross-section. Between the limbs, and at the end, of the main yoke 10 a pivot pin 14 is mounted to which both the two-armed clawed yoke 11 and the one-armed clawed yoke 12 are articulated. At the pivot pin 14 the yokes are nested within one another. A torsion spring 15 surrounds the pivot pin 14 and its ends 16 and 17 extend through recesses 18 and 19 and bear on the clawed yokes 11, 12. This torsion spring 15 is such that its ends press from above against back 20 and 21 of the clawed yokes 11 and 12.

Thus the torsion spring 15 tends to turn the one-armed clawed yoke 12 round the pivot pin 14 in the clockwise direction.

In the embodiment according to Fig. 2 all yokes are made of plastics material. The main yoke 10 is pivotally linked with the clawed yoke 11 by means of a socket and spigot as shown, and to the back of the clawed yoke 11 adjacent to the pivot the one-armed clawed yoke 12 is connected, the yokes 11 and 12 being formed in one piece.

The clawed yoke combination 11 and 12 is in one direction, normal to the plane of the window to be wiped, such that the yoke 12 is shaped so as to be resilient and so that in the unstressed condition the yoke combination has the configuration shown in Fig. 2. The three claws of the clawed yokes 11 and 12 are thereby located on one line 30, the radius of curvature of which is smaller than the smallest radius of curvature of the window to be wiped. As soon as the wiper rubber rests on the window to be wiped the one-armed clawed yoke 12 is thus subjected to forces in the counterclockwise direction and thereby resiliently stressed.

When the wiper rubber moves from a curved area of the window to a flat area the one-armed clawed yoke 12 is subjected to forces in the counterclockwise direction. In the embodiment according to Fig. 2 this motion is directly transmitted to the twoarmed clawed yoke 11 whereas in the embodiment according to Fig. 1 it is transmitted via the torsion spring 15. In both cases a pivot force acts on the two-armed clawed yoke, so that the contact pressure in the middle area of the wiper rubber, that is the portion of the rubber supported by the two-armed clawed yoke, in increased.

If, however, the wiper blade runs from the flat area of the window to the curved area the two-armed clawed yoke 11 and the yoke 12 are pivoted in the clockwise direction, the yoke 11 reacting first, because of the rigidity of the rubber, and its pivoting being either directly transmitted to the yoke 12 (Fig. 2) or via the torsion spring 15 (Fig. 1), so that the contact pressure at the end of the wiper rubber is accordingly increased.

The pivoting motion of one of the clawed yokes thus results in a change of the contact pressure exerted by the other clawed yoke, so that in the flat area of the window the contact pressure of the middle area of the wiper rubber is increased, whereas in the curved area of the window the contact pressure at the end of the wiper rubber is increased, that is, the contact pressure is distributed in accordance with the shape of the window.

In the drawings only two embodiments are shown which may be realized particularly easily in production. The yokes and also the torsion spring can be formed or supported otherwise. Especially it is also possible to arrange one claw of the twoarmed clawed yoke nearer to the pivot pin, that is, make one arm shorter. Finally also the main yoke 10 could have a claw, through which the wiper rubber is additionally supported. In the embodiment according to Fig.

2 the one-armed clawed yoke 12 could itself be rigid, and the transition area to the twoarmed clawed yoke could be formed as a resilient joint, which is easily possible due to appropriate dimensioning of the crosssection of the material. Secondary yokes 11 and 12 may be provided at one or both ends of main yoke 10, depending on the shape of the window to be wiped.

WHAT WE CLAIM IS: 1. Wiper harness assembly for distributing pressure to and holding a wiper blade rubber for cleaning an automobile window, the assembly comprising a main yoke and two secondary clawed yokes connected to one end of the main yoke so that they can pivot relative to the main yoke, one of the clawed yokes being one-armed and the other being two-armed, one of the clawed yokes being arranged for holding the end of the wiper blade rubber, wherein pivotal motion of any one clawed yoke relative to the main yoke will alter the pressure applied to the rubber by the other clawed yoke in use of the assembly.
2. Wiper harness assembly according to claim 1, wherein one clawed yoke is resiliently supported on the other clawed yoke.
3. Wiper harness assembly according to claim 1, wherein in one direction normal to the plane of the window to be cleaned one clawed yoke is shaped so as to be resilient and is pivotably fast with the other clawed yoke.
4. Wiper harness assembly according to claim 2 or 3, wherein the clawed yoke for

the end of the wiper blade rubber is onearmed and the other clawed yoke is twoarmed.
5. Wiper harness assembly according to claim 4, wherein the one-armed clawed yoke and the two-armed clawed yoke are articulated on a common pivot pin of the main yoke and resilient support is achieved by a torsion spring embracing the pivot pin, the ends of said torsion spring bearing on the backs of the clawed yokes.
6. Wiper harness assembly according to claim 4 as appendant to claim 3, wherein the one-armed and the two-armed clawed yokes are made of plastics material in one piece.
7. Wiper harness assembly according to claim 6, wherein the one-armed clawed yoke adjoins the back of the two-armed clawed yoke adjacent to the pivot.
8. Wiper harness assembly according to any one of the preceding claims, wherein the claws of the clawed yokes in the unstressed condition are located on a line the radius of curvature of which is smaller than the smallest radius of curvature of the window to be cleaned.
9. Wiper harness assembly substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Fig. 2 of the accompanying drawings.