Windshield wiper control system

• US 8,441,221 B2
• Filed: 11/19/2009
• Issued: 05/14/2013
• Est. Priority Date: 12/02/2008
• Status: Expired due to Fees

• Current Assignee: Hydreon Corporation
• Original Assignee: Hydreon Corporation
• Inventors: Teder, Rein S.
• Primary Examiner(s): Ro, Bentsu
• Assistant Examiner(s): Mustafa, Iftekhar
• Application Number:
  US12/998,689
• Publication Number:
  US 20110221372A1
• Time in Patent Office: 1,272 Days
• Field of Search: 318/66, 318/68, 318/69, 318/70, 318/483, 318/638, 318/643
• US Class Current: 318/643
• CPC Class Codes: B60S 1/0803 Intermittent control circuits
• CPC Class Codes: B60S 1/0818 including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like

Abstract

The present invention relates to a low-cost windshield wiper control system which can be readily incorporated into existing vehicle systems, particularly into an operator-accessible windshield wiper control unit assembly (100). The windshield wiper control assembly (100) is selectively operable as an intermittent wiper control system, or as a rain sensing windshield wiper control system without the need for microprocessors or multiplex circuitry.

Claims

1. A windshield wiper control system comprising:

a disconnectable rain sensor including an output capable of producing varying voltage levels, such voltage levels corresponding to a selected mode of windshield wiper operation, the control voltage outputs having an associated rain sensor output electrical resistance;

a wiper driver motor with an integrated cam assembly;

a wiring harness operatively connected to the wiper driver motor;

an operator accessible windshield wiper control unit, contained in a stalk connected to the vehicle steering column and connected to the wiring harness, the windshield wiper control unit containing a control circuit comprising;

(a) at least one mechanical switch having a plurality of electrical contacts;

(b) a rain sensor control electrical input operatively connected to the rain sensor control voltage output;

(c) an intermittent RC network operatively connected to the rain sensor control electrical input and configured to provide an intermittent delay function, and comprised of a capacitor and at least one intermittent RC network resistor, said intermittent RC network resistor being of a value at least ten times the value of the rain sensor output resistance;

(d) at least one electrical relay operatively connected to drive the wiper driver motor;

(f) a rain sensor electrical input analysis device which responds to the varying control voltages present at the rain sensor control voltage inputs, the varying control voltages driving the at least one electrical relay;

wherein

the rain sensor output resistance shunts current flowing through the intermittent RC network resistor and the windshield wiper control system operates in a rain sensing mode, but when the rain sensor control voltage output is disconnected from the rain sensor control electrical input, the windshield wiper control system operates in a conventional intermittent wiper operation mode.

2. The windshield wiper control assembly defined in claim 1, wherein a particular rain sensor output voltage level activates the headlamps of the vehicle in which the rain sensor is installed.

3. The windshield wiper control system defined in claim 1, wherein when the at least one mechanical switch comprises an off position, and when the switch is moved from the off to intermittent position, a monostable circuit provides an electrical pulse about 1 second in length, activating the wiper driver motor.