FR2465619A1 - DEVICE FOR ADJUSTING THE INTERMITTENT MOVEMENT OF A WINDSCREEN WIPER - Google Patents

Abstract

THE INVENTION RELATES TO A DEVICE FOR USE IN A ROAD VEHICLE, FOR INTERMITTENTLY CONNECTING A WIPER DRIVE MOTOR TO A CURRENT SOURCE FOR INTERMITTENT MOVEMENT OF A WIPER BLADE. ACCORDING TO THE INVENTION, IT INCLUDES A FIRST MEANS 10 PRODUCING A TUNING SIGNAL THE SIZE OF WHICH INCREASES WITH THE SPEED OF THE VEHICLE; A SECOND MEAN 20 PRODUCING A FIRST SIGNAL FOR A PREDETERMINED PERIOD AND A SECOND SIGNAL FOR A VARIABLE DURATION DEPENDING ON THE SIZE OF THE ADJUSTMENT SIGNAL APPLIED TO IT; AND A THIRD MEAN 30 CONNECTING THE DRIVE MOTOR 40 OF THE WIPER TO THE CURRENT SOURCE IN RESPONSE TO THE FIRST SIGNAL APPLIED BY THE SECOND MEAN AND DISCONNECTING THE MOTOR FROM THE SOURCE IN RESPONSE TO THE SECOND SIGNAL APPLIED BY THE SECOND MEAN . THE INVENTION APPLIES IN PARTICULAR TO THE AUTOMOTIVE INDUSTRY.

Description

The present invention relates to a training system

  a wiper for use in a road vehicle, more particularly a wiper drive system having an intermittent windshield wiper adjuster for connecting

  intermittently a wiper drive motor

ice to a power source.

  We know that for the same density of rain, the amount of raindrops on the ice of a road vehicle

  increases with increasing speed of the vehicle.

  Wiper drive systems have already been proposed including an intermittent motion control device of the manually operated wiper for adjusting the period of intermittent movement of the wiper blades. However, such traditional systems require an operator to operate the device for adjusting the intermittent motion of the windscreen wiper,

  each time the vehicle stops or starts functioning

  or at a slow speed or fast speed.

  Consequently, the subject of the present invention is a device for adjusting the intermittent motion of a wiper for automatically adjusting the period of intermittent movement of the wiper blades according to

the speed of the vehicle.

  The present invention relates to a device for adjusting the intermittent motion of a wiper for use on a road vehicle, for intermittently connecting a drive motor of the wiper to a power source. The adjusting device comprises a first means producing a control signal whose magnitude increases with the speed of the vehicle. The first means comprises a voltage divider connected to a voltage source and having a series connection of a number of resistors, and at least one switching means connected to one of the resistors. The switching means operates to increase the output of the first means when the speed

  the vehicle moves to a higher speed range.

  The exit of the first ground is connected to a second ground

  which produces a first signal for a predetermined period of time

  time and a second signal for a variable period of time depending on the magnitude of the signal at the output of the first means. The second means employs an astable multivibrator in a preferred embodiment. Alternatively, the second means may comprise a capacitor charged by the output of the first means and discharged by a

discharge circuit.

  The output of the second means is related to a third means. The third means is responsive to the first signal applied thereto by the second means for connecting the wiper drive motor to the power source. Similarly, the third means is responsive to the second signal applied to it by the second means for disconnecting the drive motor from the windscreen wiper.

of the current source.

  With the device for adjusting the intermittent motion of a windscreen wiper according to the invention, thus the period of intermittent movement of the wiper drive motor can be reduced with a constant training time and time. reduced rest while the '

vehicle speed increases.

  The invention will be better understood and other purposes, features, details and advantages thereof

  will appear more clearly during the description

  explanatory text which will follow with reference to the appended schematic drawings given solely by way of example illustrating several embodiments of the invention and in which: FIG. 1 is a circuit diagram showing

  an embodiment of a movement control device

  intermittently of a wiper according to the present invention; FIG. 2 contains three waveforms 2a, 2b and 2c obtained at various points in the circuit diagram of FIG. 1; Fig. 3 is a circuit diagram showing a second embodiment of the present invention; and FIG. 4 is a graph of three charge curves of a capacitor useful for explaining the

  operation of the movement control device

  the windscreen wiper according to FIG.

  Referring first to FIG. 1, it illustrates an embodiment of a device for adjusting the intermittent motion of a windshield wiper constructed in accordance with the present invention. The adjusting device comprises a generator 10 of adjustment signals producing a control signal Va whose magnitude increases with the speed of the vehicle. The generator 10 consists of a series connection of resistors R1 to R4. The free end of the resistor RI is connected to a constant voltage source + "and the free end of the resistor R4 is grounded.A start switch S1 is connected in parallel with the resistor R3. is closed when the road vehicle is stationary and opens after the vehicle has started operating, the SI switch may be associated with a vehicle speedometer so that it can be kept open except when the counter indicates zero speed.

  SI switch may be in the form of an electronic switch

  associated with a digital-type vehicle type indicator or speedometer so that it can

  be kept open except when a null indication.

  is given on digital reading. A top speed switch S2 is connected across the resistor R2. The switch S2 can be associated with a transmission so that it can be kept open except when

  the transmission is put in position of higher speed.

  When the vehicle is stationary, the ignition switch

  SI start is closed and the upper speed switch

  S2 is open, and a very low voltage setting Val appears at point a o are joined the resistors R2 and R3. When the vehicle begins to roll, the SI start switch opens to increase the voltage of the vehicle.

  setting Go to a value Va2 greater than the value Val.

  When the speed of the vehicle increases and the transmission

  is placed at its top speed position, the switching

  speed controller S2 closes to further increase the adjustment voltage Va to a higher value Va3

at the value Va2.

  The signal at the output of the regulation signal generator 10 is applied to a control circuit 20 which contains a conventional astable multivibrator having first and second transistors TR1 and TR2. The emitter of the first transistor TR1 is grounded, and its collector is connected by a first resistor R5 to the voltage source and also by a first capacitor C1 and a second resistor R6 to the voltage source. The basis of the second

  transistor TR2 is connected to the junction of the first condensa-

  C1 and the second resistor R6. The emitter of the second transistor TR2 is grounded and its collector is connected to the output e of the astable multivibrator. The collector of the second transistor TR2 is further connected by a third resistor R8 to the voltage source, and also by a second capacitor C2 and a fourth resistor R7, to the output a of the control signal generator 10. The junction d of the second capacitor C2 and the fourth resistor R7 is connected to the base of the

first TRM transistor.

  The output e of the astable multivibrator is connected to the base of a switching transistor TR3 whose colectmwr is connected by the coil 22a of a relay 22 to the voltage source. The emitter of the transistor TR3 is connected to a fixed contact INT of a wiper switch 30. The switch 22b of the relay 22 is kept closed to connect

  a terminal C of a drive motor 40 of the wiper

  ice while the flow of current occurs through the coil 22a. The wiper switch 30 has three further fixed contacts BA, HA and ARR and a movable contact connected to ground. The fixed contact BA is connected to the terminal C of the wiper drive motor 40 for a continuous rotation of this motor 40 at a low speed. The fixed contact HA is connected to a terminal B of the motor 40 for a continuous rotation of this motor at a high speed. The motor 40 has a terminal A which

  is connected to the voltage source.

  Referring now more specifically to

  Figure 2 shows three voltage waveforms

  time. FIG. 2a illustrates a waveform of the voltage Vd appearing at point d where the resistor R7 and the capacitor C2 are joined. Figure 2b illustrates a shape

  wave of the voltage Ve appearing at point e, that is to say

  say at the output of the astable multivibrator.

  The astable multivibrator produces, at its output e, a rectangular pulse Ve which can be seen in FIG. 2b. The time t during which the signal Ve is kept at its high level (Vvols) is determined at a fixed value by the values of the capacitor C1 and the resistor R6 and the fixed voltage (V vol * W of the source, while the time t 'during which the signal Ve is kept at its low level (zero volts) depends on the magnitude of the adjustment voltage Va appearing at the output of the

  generator 10 of adjustment signals.

  When transistor TR2 becomes conductive, voltage V goes from V volts to zero volts. This causes a voltage drop of V volts at point d, rendering transistor TR1 nonconductive. Since the point d is connected by the resistor R7 to the control voltage Va, the capacitor

  C2 charges to gradually increase the voltage Vd.

  When the voltage Vd reaches zero volts, the transistor TR1 becomes conductive, which makes the transistor TR2 non-conductive. Consequently, the higher the adjustment voltage Va, the faster the rate at which the voltage Vd is increased as shown by the waveform 2a, and thus shorter is the time t 'during which the voltage Ve is It is held at its low level as shown by waveform 2b and shorter is the period T of signal Ve. It can be seen in FIG. 2a that the time t 'is at a value tl' and that the period T is at a value Ti for the set voltage value of Val, the time t 'is at a value t2', plus short time tl '; and the period T is at a value T2 shorter than T1 for the adjustment voltage Va2 and the time t' is at a value t3 ', shorter than the value t2', and the period T is at a value T3 shorter than the value T2 for the adjusting voltage value Va3. In the INT position of the wiper switch 30 which is shown in FIG. 1, when the output signal Ve goes high, the transistor TR3 becomes conductive to allow current flow in the coil 22a to close. the switch 22b of the relay to force a voltage Vm (equal to V flies) between

  terminals A and C of the wiper drive motor 40

  ice cream, to train him. When the output voltage Ve goes low, the transistor TR3 becomes non-conductive to interrupt, the current flow in the relay coil 22a to open the switch 22b. After

  return the wiper blade to a predefined position

  where it causes the change of a switch

  stopping (not shown), the motor 40 is de-energized

and stops turning.

  Figure 2c illustrates the voltage waveform

  Vm appearing between terminals A and C of motor 40.

  It can be seen in Figure 2c that the rest period Z

  during which the drive motor of the wiper

  ice 40 is stopped, decreases while the adjustment voltage VI increases. The rest time I is at a value Z7 for the value Val of. adjustment voltage, to a value ZC2 shorter than the value T-i for the value Va2 of the adjusting voltage and to a value T 3 shorter than the value 7, 2 for the value Va3 of

the adjustment voltage.

  In this way, the duration of the intermittent movement of the wiper motor 40 can be reduced with a constant training time and a reduced rest period while

  as the speed of the vehicle increases.

  Although the start switch is of the type associated with a vehicle speedometer in this embodiment, it will be appreciated that a dead-point switch may be used, producing a signal when the

transmission goes into neutral.

  Referring now to FIG. 3, it illustrates a second embodiment of the present invention where like parts are designated by like reference numerals, whereas like parts having identical functions are desig- nated by the same reference numerals as those used in Figure 1, followed

of the sign '.

  A windshield wiper switch is schematically shown at 30 ', and it connects the M and L contacts to its ARR position, the I and E contacts and also the M and L contacts to its INT position, the E and L contacts.

  at its position BA and the contacts E and H at its position HA.

  Contact E is grounded. H and L contacts are connected to terminals B and C for fast and slow speeds

of the motor 40, respectively.

  The generator 10 'of control signals in this embodiment is substantially similar to that of Figure 1 except that a variable resistor VR is interposed between the resistors R3 and R4, which allows a manual adjustment of the voltage of setting Va appears at the output of the generator 10 'and thus the duration of the intermittent movement of the motor 40 of the wiper drive. The presence of

  VR variable resistor is optional.

  The signal at the output of the generator 10 is applied to a control circuit 20 ', different in structure from that of the first embodiment. In the 9th circuit 20 'is used an integrated circuit 26 having an output terminal 1, a power terminal 2, a ground terminal 3, an establishment-recovery terminal 4, a windshield washer terminal 5 (which does not is not part of the invention) and an input terminal 6. The terminal 1 of the circuit 26 is connected to one end of a relay coil 28a, the other end is connected to the voltage source. The coil 28a is associated with a relay switch 28b whose movable contact a is held in connection with the fixed contact b as shown in FIG. 3 when there is no current flow in the relay coil. 28a and goes into connection with the fixed contact c when there is current flow in the coil 28a. The terminal 4 of the circuit 26 is connected to the contact I of the wiper switch 3 'and also by a resistor R9 to the voltage source. The terminal 6 is connected by a capacitor C3 to the ground and also by a resistor R10 to the adjustment voltage Va. Terminal 6 is further connected by a series circuit of a resistor

  R11 and a diode D at terminal 1.

  A voltage regulator circuit 50 is provided for

  provide a constant voltage at terminal 2 of circuit 26.

  The voltage regulator circuit 50 comprises a series circuit of a resistor R12 and a capacitor C4 connected between the voltage source and the ground, and a diode

  Zener ZD connected in parallel with the capacitor C4.

  The positive end of Zener diode ZD is connected to

terminal 2 of circuit 26.

  An auto-off switch is illustrated at 60, the movable contact d of which is held in connection with the fixed contact e as illustrated in FIG. 3 when the wiper drive motor 40 is in position. stop and it goes into connection with the fixed contact

  when the engine 40 begins to turn. The switch

  60 is associated with the wiper blade, so the movable contact d can be connected to the fixed contact e when the wiper reaches a position

  predetermined. The movable contact d of the auto switch

  stopping is connected to the fixed contact b of the switch 28b.

  The fixed contact c of the switch 28b is grounded and its movable contact a is connected to the contact M of the wiper switch 301. The fixed contact e of the auto-stop switch 60 is connected to the voltage source and its

fixed contact f is grounded.

  In the INT position of the wiper switch 30 ', the terminal 4 of the circuit 26 is grounded by the contacts I and E of the switch 30' to put the integrated circuit into operation. Since the capacitor C3 has been charged to maintain the terminal 6 above a predetermined high level VH, the terminal 1 is grounded by means of the terminal 3. Accordingly, there is a current flow in the relay coil 28a for changing the movable contact a of the switch 28b and put it in connection with the fixed contact c. This produces a connection of the slow-speed terminal C Eliminated drive motor 40

  to ground via the M and L contacts of the wiper switch

  30 'to start the rotation of the drive motor.

40.

  In the state of the circuit, the capacitor C3 quickly discharges into a discharge circuit containing

  the resistor R11, the diode D and the terminal 1 of the circuit 26.

  When the voltage at label 6 drops below a predetermined low level Vl, the voltage at terminal 1 goes high (V volts) to interrupt the current flow in relay coil 28a in order to switch on the ignition. mobile switch 28b in connection with the fixed contact b. Since the movable contact d of the auto-stop switch 60 is held in connection with the fixed contact f after switching on the motor 40, the terminal C of the motor 40 is kept grounded by the wiper switch 70, the relay switch 28b and the auto-off switch 60, so the motor 40 can remain in rotation. When the wiper blade returns to its predetermined position, the auto-stop switch 60 returns to its initial position, which can be seen in FIG. 3, to produce a short circuit between terminals A and C motor 40 to stop the rotation of the latter. When the voltage at terminal 1 of circuit 26 passes

  in the high state, the adjustment tension Va gradually load-

  capacitor C3 by means of the PM resistor. When the voltage in the capacitor C3 reaches the predetermined high level VH, the voltage at the terminal 1 of the circuit 26 falls back to ground level, so as to set the windshield wiper motor 40 in the same way as 'we

described above.

  FIG. 4 shows three capacitor charge curves. It can be seen in FIG. 4 that the higher the adjustment voltage Va, the less time it takes for the voltage in the capacitor C3 to go from the predetermined low level VL to predetermined high level VH, that is to say the rest period during which the motor is at a standstill The time is at a value tlu for the set voltage value of Val, at a value t2 ", plus short that ti ", for the set voltage value Va2 and a value t3" shorter than t2 ", for the value

setting voltage Va3.

  In this way, the duration of intermittent movement of the drive motor 40 can be reduced with a constant drive time and a reduced idle time.

  as the speed of the vehicle increases.

  Naturally, the invention is not limited to the embodiments described and shown which have been given by way of example. In particular, it comprises all the means constituting technical equivalents of the means described as well as their combinations if they are executed according to its spirit and put

  implemented in the context of protection as claimed.

Claims (8)

REVEND I C AT I 0 N S   1. Device for use in a road vehicle for intermittently connecting a wiper drive motor to a power source for intermittent movement of an ice-cream broom, characterized in that it comprises: first means (10, 10 ') producing a control signal whose magnitude increases with the speed of the vehicle; - -   second means (20, 20 ') producing a first signal for a first predetermined duration and a second signal for a variable duration depending on the magnitude of the adjustment signal applied thereto; and third means (30, 30 ') for connecting the drive motor of the wiper (40) to the current source in response to the first signal applied thereto by said second means and for disconnecting said motor from entralnement of said source in response to the second signal which is applied by said second means.   2. Device according to claim 1, characterized in that the first aforementioned means comprises a voltage divider bridge connected to a source of voltage and having a series connection of a number of resistors (R1, R2, R3, R4), and switch means having at least one switch (S1) connected across one of the resistors and operable to increase the magnitude of the control signal when there is an increase the speed of the vehicle.   3. Device according to claim 2, characterized in that the aforementioned switching means consists of a switch that can operate except when the vehicle is stopped.   4. Device according to claim 3, characterized in that the predicted switching means further comprises a second switch (S2) operable when the vehicle operates with its transmission in position of top speed.   5. Device according to claim 2, characterized in that the aforementioned voltage divider bridge further comprises a variable resistor (VR) connected in series with the aforementioned series connection of resistors - 6. Device according to claim 1, characterized in that it further comprises a self-stop switch   (60) to hold the drive motor of the wiper   aforesaid ice-cream connected to the above-mentioned power source until   what the wiper blade returns to its position-   predetermined after the second aforementioned signal.   7. Device according to claim 1, characterized in that the second aforementioned means comprises a first transistor (TR1) whose emitter is set to: mass and 1 = whose collector is connected by a first resistor (R5) to the voltage source and also by a first capacitor (C1) and a second resistor (R6) to said voltage source, a second transistor (TR2) whose base is connected to the junction of the first capacitor and the second resistor, whose emitter is grounded and whose collector is connected directly to the third aforementioned means, by a third resistor (R8) to the voltage source, and by a sec-capaccator (C2) and a fourth resistor (R7) at the output the first aforementioned means, the junction of said second capacitor and said fourth resistance being connected to the base said first transistor.   8. Device according to claim 1, characterized in that the second aforementioned means comprises a capacitor (C3) whose negative armature is connected to the ground and the other armature is connected by uxepremre resistance (R10) to the output of the first aforesaid means, and means (R11, D, 26) allowing said capacitor to discharge in a second resistor (R11) for applying the first signal to the third aforementioned means when the voltage at the positive armature of said capacitor is above a first level and applying the second signal to said third means when the voltage at the positive armature of said capacitor is below a second level, less than the first.