Device including wetness sensor for controlling a windshield wiper

• US 5,157,312 A
• Filed: 10/22/1990
• Issued: 10/20/1992
• Est. Priority Date: 12/02/1989
• Status: Expired due to Fees

• Current Assignee: VDO Adolf Schindling AG (Vodafone Group PLC)
• Original Assignee: VDO Adolf Schindling AG (Vodafone Group PLC)
• Inventors: Wallrafen, Werner
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US07/601,936
• Time in Patent Office: 729 Days
• Field of Search: 15/250 C, 15/250.12, 15/250.13, 15/250.17, 312/443, 312/444, 312/DIG. 2, 312/483, 312/264, 312/62, 312/446
• US Class Current: 318/264
• CPC Class Codes: B60S 1/0818 including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
• CPC Class Codes: B60S 1/0825 Capacitive rain sensor
• CPC Class Codes: Y10S 318/02 Windshield wiper controls

Abstract

In a device for controlling a windshield wiper, in particular on a motor vehicle, the windshield wiper is switched on when a sensor indicates wetness above a preset threshold value. The windshield wiper can furthermore be turned on by a manually actuatable switch. The threshold value is reduced upon actuation of the switch.

Claims

1. A device for controlling a windshield wiper, suitable for a motor vehicle, the device comprising

a sensor of windshield wetness, and a manually actuated switch;

and

a computer, the computer being coupled to the sensor and the switch, and outputting a control signal for driving a windshield wiper; and

wherein the computer is operative to activate the windshield wiper if the sensor indicates wetness above a predetermined threshold value;

the windshield wiper can be activated by the manually actuated switch; and

the threshold value is reduced upon actuation of the switch.

2. A device according to claim 1, wherein

said threshold value is reduced upon actuation of the switch to approximately the output voltage given off by said sensor.

3. A device according to claim 1, wherein

after an activation of the device, a threshold value selected by the computer assumes a value which is equal to or less than the output voltage given off by said sensor at the time of the activation of the device.

4. A device according to claim 3, wherein

upon an actuation of the device after a predetermined period of time, a threshold value selected by the computer assumes the threshold value last present, which has been stored.

5. A device according to claim 3, wherein

upon a further activation of the device, a threshold value selected by the computer, after a predetermined period of time, assumes a value which lies approximately at an output voltage given off, at the time, by the sensor.

6. A device according to claim 1, wherein

said computer operates in response to a program to regularly interrogate said sensor and said switch;

said computer switches the windshield wiper on or off upon the exceeding of a threshold value by said wetness indicated by said sensor, and upon actuation of the switch; and

in response to a setting of the switch, said computer adjusts the threshold value as a function of an existing sensor signal.