METHOD OF DRIVING WINDSHIELD WIPER

PURPOSE:To change the pressure of the blade of a windshield wiper depending on the swing velocity of the blade, by altering the mechanical displacement of the blade perpendicular to the surface of the windshield, depending on the quantity of operation of a wiper switch. CONSTITUTION:A wire 34 extends through a hollow wiper shaft 4. One end of the wire 34 is connected to a holder 6 for a wiper arm 1 and the other end is coupled to the shift lever 20 of a wiper switch through an arm pressure control spring 33. A wiper controller 21 regulates a driving motor 22 in accordance with the set mode of the shift lever 20. When the mode of the shift lever 20 is sequentially changed to rotate the driving motor 22 intermittently, slowly and rapidly in that order, the spring 33 is elongated depending on the displacement of the lever to cause restoring force. The restoring force is transmitted through the wire 34 to push the wiper arm 1. The pushing force increases according to the elongation of the spring 33.