FR2557725A1 - Windscreen wiper automatic contactor. - Google Patents

Abstract

The invention relates to a windscreen wiper automatic contactor should water be detected on the windscreen. It is characterised in that it comprises a contactor 8 driven by a relay 9 controlled by an electronic circuit 1 itself comprising a sensor 2 formed of two conductive strips which are separate but nevertheless sufficiently close so that water falling on the said sensor 2, at a certain density, is able to connect the two conductive strips 3 and thus control the electronic circuit 1. Application to the automobile industry.

Description

the invention relates to an automatic wiper switch 57 in the event of detection of water on the windshield.

This contactor finds more particularly, but not exclusively, application in the automotive industry
Currently the wiper control means are manual by conventional switch. There are also the wiper cadmers5 which trigger them intermittently. But in all cases there is manual intervention.

 The result which the invention aims to obtain is the total automation, as soon as there is a little water on the windshield, of the wiper control.

The invention will be better understood with the aid of the description below given by way of nonlimiting example with regard to the attached drawing which represents
fig i: diagram of the water sensor
fig 2: block diagram of electronic operation.

fig 3: installation of the sensor on the windshield
fig 4 and 5: sectional view of the self-adhesive sensor
By referring to the drawing we see that on one at
to sticky 2 transparent of an arc shape, by
example centered on the wiper axis and arranged
the base of the swept sector does not interfere in any way with the visi
bility, are engraved, by electroplating, thermo bonding or
by any other known method, two conductive strips 3.

Their spacing depends on the. rain density required to trigger the electronic contactor. These two conductive strips 3 are connected to two flexible wires 4, 5 joining the electronic circuit 1
In series on 11 circuit supply are placed a switch 6 for automatic on or off only allowing a conventional manual control and a fuse 7 limiting the intensity of the current.

 the connections of the contacts 8 of the relay 9 are made in parallel with the original connection of the windscreen wipers, which makes it possible to maintain the possibility of manual intervention.

 The oscillator 10 emits a square signal whose frequency t depends on the value of the resistor 11 and of the capacitor 12. This signal is brought by a flexible wire 4 to the sensor 2. If it rains, it rains as much on the windshield than on the sensor. This square signal corresponding to an alternating current avoids electrolysis phenomena at the level of the sensor.

At a certain density of water the contact is
bli between the two conductive strips 3. The resistance
that tiny that existed when there was no water
drops sharply and the signal passes through the water between
two conductive strips 3, by the flexible wire 5 being
brought after rectification by diodes 13 and 14.

A logical "1" is born at the base of the door
16. the output of this gate is therefore negative, polarizing the base of transistor 17.

relay 9 is thus energized, starting the wiper motor. the brooms filling their
function also wipe the two conductive strips
these 3 self adhesive 2.

 If it rains hard enough the contact is perpetuated between these two bands 3 and the wiper continues to operate.

If it stops raining, the brooms scraping the water
of the sensor, the contact between the strips 3 is quickly interrupted. The signal no longer passing through the diodes
13 and 14 no longer rectify anything and the capacitor 18
discharging via resistor 15, the base of door 16 becoming negative, its output is
positive, transistor 17 no longer allows excitation
relay 9. the windshield wipers therefore stop.

In addition, the above diagram more fully
described is only a preferred embodiment
from which one skilled in the art will be able, without
work of invention find many variations.

tiny wires 4 and 5 go under the car
sticky 2 and come out through the metal strips 3,
given their finesse the weld is really pla
which allows the wiper blade 24 to scrape
water easily.

 the wires can also be placed before X 57 treatment by gavanoplasty of the bands 3, therefore there is no longer any visible protuberance.

 These wires can Other replaced over a certain length by also conductive strips 23 on the internal face of the self-adhesive and connect to the wires 4 and 5 between the limit 19 of the external strips 3 and the edge 22 of the self-adhesive but on the inner side at half distance.

 the strips 3 preferably start and end with rounded or angular edges to be more easily overlapped by the rubberized squeegees24.

In fact to facilitate the realization of the sensor 2 two self-adhesive plastic films can be joined with recesses provided in the necessary places
to receive the conductive layers, see fig 4-5 of
the self-adhesive in section, or we see respectively the ban
conductors 3d arranged in the recesses of the faces
upper (fig 4 corresponding to section AA in fig 1)
and lower (fig Sc corresponding to the section BB of fig 1)
wires 4 and 5 go under the sticky tape and there
are extended, at a distance, by bands also con
23 which come out on the outside of the car
sticky becoming the strips 3 so that the brooms
24 finish their race before the rounded start 9 of the strips 3 so that there is no contact by the wiper blades, the virgin start 22 starting before the stroke limit of the broom. The strips 3 end in 20 on the other side, also before the end of the brush stroke so that the scraping is complete, the self-adhesive blank ending in 21 after the brush stroke limit.

The end of the 20 extends and passes under the auto collar
lant by 25 joining the underside as for
conductive strips 23 and this to avoid the risks of
separation of the strips 3 when the squeegees return
of their limit switch 26.

Claims (8)

R3V-NDICAnIOPtS 1. Automatic wiper switch in the event of water detection on the windshield, characterized in that it comprises a contactor 8 controlled by a relay 9, controlled by an electronic circuit 1 itself comprising a sensor 2 formed by two conductive strips 3 on an insulating support which are distinct but nonetheless sufficiently close that the water falling on said sensor 2, at a certain density, can connect the two conductive strips 3 and thus control the electronic circuit 1. 2. Automatic wiper contactor according to claim 1 characterized in that the sensor 2 can  transparent be a self-adhesive allowing by its formal scraping of water from the conductive strips by the wiper blades. Its shape accompanying the movement of the wiper blade 24, and in that the sensor 2 is connected to the electronic cooked circuit 1 by two electric wires 4 and 5. 3. Automatic wiper switch according to claims 1 and 2 characterized in. that the contactors 8 of the relay 9 is connected in parallel to the wiper control circuit already existing, allowing independent use of the automation due to the invention.  4. Automatic wiper switch according to claims 1 to 3 characterized in that the signal emitted  in the sensor is a square wave which corresponds to  an alternating current therefore not subject to electrolysis.  * N3. in an arc intended to be arranged at  the base of the sweeping sector, 6. Automatic wiper switch according to one of claims 1 to 5 characterized in that the tiny wires 4, 5, are placed before depbttpar electroplating, bonding, heat bonding or any other process, conductive layers 3, so that these strips 3 are integral with the wires 4, 5, without it being necessary to solder them. 7. Automatic switch dtessuieglace according to one set of claims 1 to 6 characterized in that the wires 4 and 5 pass under the auto collanta 6 'are extended over a length at mid distance by equally conductive strips 23 which stand out on the face external of the self-adhesive tape becoming the strips 3 so that the wiper blades 24 finish their race before the rounded start 9 of the strips 3 so that there is no contact by the wiper blades , the virgin start 22 beginning before the broom stroke limit. 8. Automatic wiper switch according to all of claims 1 to 7 characterized in that the conductive strips 3 terminentsen rounded or angularly 20d before the end of stroke of the brushes so that the scraping of the strips is total, the virgin self-adhesive finishing after the brush stroke limit.  9. Automatic wiper switch according to one set of claims 1 to 8 characterized in that the sensor 2 can other made by two self-adhesive plastic films, one superimposed on the other, and recesses provided in the places necessary for receive the conductive layers, the layers of the strips 3 joining the layers 23. 10. Automatic wiper switch according to all of claims 1 to 9, characterized in that the end of the strips 20 is extended and passes under the slow-moving auto by joining the lower face as for the  23 in order to avoid the risks of detachment.