WHEEL FOR A VEHICLE WINDOW WIPER DRIVE SYSTEM

Abstract

1. Wheel (100) far a vehicle window wiper drive system, said wheel comprising electrical contact means (400), a first and a second electrical contact means (410, 411) of said electrical contact means being in electrical continuity, and the first and the second electrical contact means being for a respective slider (200a, 200b), said wheel being characterized in that the angular extension (a) of said electrical contact means in the plane of the wheel is strictly less than 360 and said electrical contact means being situated on a face of the wheel intended to receive a linkage.

Claims

1. A wheel for a vehicle window wiper drive system, said wheel comprising: electrical contact means, a first and a second electrical contact means of said electrical contact means being in electrical continuity, and the first and the second electrical contact means being for a respective slider, wherein the angular extension of said electrical contact means in the plane of the wheel is strictly less than 360°, and wherein said electrical contact means is situated on a face of the wheel for receiving a linkage.

2. The wheel according to claim 1, wherein the angular extension of the electrical contact means in the plane of the wheel is less than 45°.

3. The wheel according to claim 1, wherein the first and second electrical contact means are combined and form a single conductive stud arranged radially.

4. The wheel according to claim 1, wherein the first and second electrical contact means each comprise a stud connected by a conductor.

5. The wheel according to claim 1, further comprising an electrically conductive segment in the form of a circle arc forming the first electrical contact means, said circle arc segment comprising a radial protrusion forming the second electrical contact means.

5. The wheel according to claim 5, wherein the face of the wheel comprises a first track and a second track for a respective slider, the first track being partly formed by the circle arc segment and the second track being partly formed by the protrusion.

7. The wheel according to claim 6, wherein the circle arc segment extends along a circular rib provided on the face of the wheel, said circular rib being intended to isolate the sliders electrically when they slide on a respective track of the wheel.

8. The wheel according to claim 7, wherein the rib comprises an interruption, the protrusion at least partially occupying said interruption.

9. The wheel according to claim 7, wherein the rib carries one of the tracks.

10. The wheel according to claim 9, wherein at least one of the ends of the interruption forms a ramp.

11. The wheel according to claim 7, wherein the rib extends between the first and the second tracks.

12. A reduction gear housing for a vehicle window wiper drive system comprising a wheel according to claim 1.

12. The reduction gear housing according to claim 12, further comprising a cover, the inner face of said cover comprising a first and a second electrically conductive slider, one end of the first slider being intended to come into contact with the first electrical contact and one end of the second slider being configured to come into contact with the second electrical contact in one position of the wheel and when the cover is closed.

14. The reduction gear housing according to claim 13, wherein: the radial position of the end of the first slider is identical to that of the first electrical contact and the radial position of the end of the second slider is identical to that of the second electrical contact, and the angular sector contained between the ends of the first and second sliders is equal to the angular sector contained between the first and second electrical contacts.

15. A drive system for a vehicle window wiper, comprising a motor and a reduction gear housing according to claim 12.

16. A system for wiping a motor vehicle window, comprising: a drive system according to claim 15; and at least one wiper blade.

Description

[0037] Embodiments and variants are described below as non-limitative examples, with reference to the attached drawings in which:

[0038] FIG. 1 shows in perspective a wheel for a vehicle window wiper drive system comprising a single stud,

[0039] FIG. 2 shows in perspective the wheel comprising two studs with an angular offset,

[0040] FIG. 3 shows in perspective the wheel comprising an annular segment with a protuberance,

[0041] FIG. 4 shows in perspective an enlarged view of the slider contact zone, illustrating an embodiment with a rib,

[0042] FIGS. 5A to 5C show diagrammatically three embodiments of the annular segment and of a rib in plan view,

[0043] FIG. 6 shows in perspective a vehicle window wiper drive system comprising a motor and a reducing gear housing, with the cover of the reducing gear housing removed, and

[0044] FIG. 7 is a diagrammatic, perspective view of a system for wiping a vehicle window using the window wiper drive system in FIG. 6.

[0045] FIG. 1 illustrates a wheel 100 for a vehicle window wiper drive system, comprising an axial hub 101 and an eccentric housing 102 for a connecting rod, and able to be driven in the direction of arrow F. To this end, it comprises teeth or notches 120 on its periphery in order to be driven by engagement, but it could also be driven by any other means.

[0046] A first and a second slider 200a, 200b are also shown which are not integral with the wheel but are useful for understanding of the invention. The ends 210a, 210b of the sliders are intended, in operation, to slide over an annular portion 110 of the wheel, situated on the edge of the wheel 100 in the example of FIG. 1. This annular portion 110 in fact forms a first and a second track 111a, 111b for a respective slider 200a, 200b, shown in parallel, the first track 111a being the outer track and indicated (partially) in short dashes, the second track 111b being the inner track and indicated (partially) in long dashes. The wheel 100 is made of non-conductive material, such that the circuit between the sliders is open when they are sliding over their respective tracks.

[0047] The wheel here illustrated has electrical contact means comprising a first and a second electrical contact means that are combined and form a single conductive stud 300. The annular portion 110 comprises an electrically conductive stud 300, for example metallic, forming an electrical contact means and arranged so as to cover the first and second tracks. When, during rotation of the wheel 100, the ends 210a, 210b pass over the stud 300, this short-circuits the first and second sliders and creates a pulse or top for a controller placed further downstream and not shown. This pulse gives the controller information on the angular position of the wheel and hence of the wiper arm.

[0048] In the example of FIG. 1, the single stud 300 is arranged radially such that its angular extension is limited to a few degrees. It may be attached to the wheel by any known means (gluing etc.). It may protrude slightly beyond the plane of the annular portion 110 or be housed in a groove on the annular portion 110 so as not to protrude.

[0049] One drawback of this embodiment is that the sliders, although not parallel, are very close together, which firstly is not always compatible with the dimensions of the sliders and secondly risks creating undesirable short-circuits between the sliders.

[0050] FIG. 2 illustrates a second embodiment of the wheel 100 in which the sliders have been omitted for greater clarity. In this second embodiment, the wheel 100 comprises electrical contact means comprising a first stud 310a that forms a first electrical contact means and a second stud 310b that forms a second electrical contact means. The wheel 100 comprises an annular portion 110 with a first and a second track 111a, 111b. The first track 111a comprises the first stud 310a and the second track comprises the second stud 310b, both electrically conductive and offset angularly but connected by a conductor 310c and fixed to the annular portion by any known means; the conductive wire 310c may for example be housed in a groove provided in the face of the wheel intended to receive a linkage. The studs may consist of bars, contact plates or other. As shown, the first and second studs 310a, 310b are angularly offset by an angle a close to 45°.

[0051] In this embodiment, the ends 210a, 210b of the sliders are offset by the same angle α so as to pass simultaneously over a respective stud 310a, 310b during rotation of the wheel 100. As in the first embodiment, the simultaneous passage of the sliders over a respective stud puts the sliders into short-circuit.

[0052] FIG. 3 illustrates a third embodiment of the wheel 100. In this embodiment, the electrical contact means 400 comprise a conductive circle arc segment 410 or mini-cam, for example metallic, fixed to the annular portion 110 by any known means (gluing, hot plastic riveting etc.) and forming the first electrical contact means. The circle arc segment 410 comprises a so-called inner edge facing the axis of rotation of the wheel, and a so-called outer edge facing the edge of the wheel. Such a circle arc segment is generally arranged close to the edge of the wheel for better measuring precision.

[0053] The circle arc segment 410 comprises a radial protrusion 411 on one edge, here its outer edge, and forming the second electrical contact means. The first track 111a of the first slider 200a comprises the protrusion 411, the second track 111b of the second slider 200b comprises the circle arc segment 410. An electrical contact is created between the first and second sliders when their respective ends slide over the circle arc segment 410 and the protrusion 411.

[0054] In this embodiment, the first electrical contact means 410 and the conductor connecting the first and second electrical contact means are combined.

[0055] As shown, the angular extension a of the electrical contact means 400, which here corresponds to that of the circle arc segment 410, is close to 90°.

[0056] As shown on FIG. 3, there are angular positions of the wheel in which the end 210a of the first slider 200a is very close to the outer edge of the circle arc segment 410, and hence in which there is a risk of undesirable short-circuit between the sliders. The invention proposes several solutions for avoiding this risk.

[0057] FIG. 4 illustrates a first variant of the third embodiment. In this variant, the face of the wheel intended to receive a linkage comprises a circular rib 500 which rises from the plane of the wheel, and hence from the annular portion 110, by a height h. It is sufficiently wide to carry the first track 111a on its top. The rib 500 comprises an interruption 501 in which the protrusion 411 of the circle arc segment 410 lies, this protrusion forming part of the first track 111a.

[0058] In this way, when it slides over the rib 500, the end 210a of the first slider 200a is axially spaced from the end 210b of the second slider 200b, avoiding the risk of undesirable short-circuit.

[0059] In FIG. 4, the rib 500 forms a raised edge of the wheel 100 but it could be arranged at any other location on the face of the wheel.

[0060] In order to facilitate the passage of the end 210a of the first slider 200a from the top of the rib 500 to the protrusion 411 and vice versa, each end of the interruption 501 of the rib 500 comprises a ramp 510a, 510b.

[0061] This variant is indicated diagrammatically in top view on FIG. 5A.

[0062] FIG. 5B illustrates a variant of the third embodiment. In this variant, a narrow rib 530 rises above the annular portion 110 and extends along the outer edge of the circular arc segment 410, the rib and the segment preferably being in contact with each other. The rib therefore extends between the two tracks 111a et 111b.

[0063] In operation, the sliders both slide over the annular portion 110 of the wheel 100, and the rib ensures the electrical isolation between the two sliders 200a, 200b. As in the preceding variant, the rib 530 comprises an interruption to allow integration of the protrusion 411 in the first track 111a.

[0064] FIG. 5C illustrates another variant of the third embodiment. In this variant, the narrow rib 530 extends along the inner edge of the metallic circle arc segment 410. The rib again extends between the two tracks 111a and 111b and ensures the electrical isolation between the two sliders 200a, 200b. It comprises an interruption to allow integration of the protrusion 411 in the second track 111b.

[0065] In the variants of FIGS. 5B and 5C, the rib 530 is spaced apart from the edge of the wheel 100.

[0066] In another variant (not shown), the rib 500 is situated along the inner edge of the circle arc segment 410 and then carries the second track 111b.

[0067] FIG. 6 shows a drive system 620 for a vehicle window wiper blade comprising a wheel 100 according to the invention. This system comprises a reduction gear housing 600 and a motor 610. The wheel 100 is housed in a space in the housing and mounted so as to rotate about a shaft 601 which is situated in the hub 101. It comprises a circle arc segment 410 according to the third embodiment. The figure also shows the first and second sliders 200a, 200b which are integral with a cover of the housing 610 (not shown for greater clarity). An endless screw 602 driven by the motor 610 engages on the notches 120 of the wheel 100. The housing also comprises a linkage composed of two arms, a first arm 603 mounted so as to rotate in the eccentric housing 102 of the wheel, one end of which arm engages with a toothed wheel integral with a drive rod 605 of a window wiper blade, and a second arm 604 mounted on the first arm 603 so as to rotate around the rod 605.

[0068] FIG. 7 shows a wiper system 9, here comprising two wiper blades 10, each comprising a drive arm 11, one end of which is connected to a blade 12 and the other opposite end of which is connected by a linkage or rod systems 13 to an output shaft of the drive system 620, such as that in FIG. 6.