AUTOMATIC RAIN AND FOG SENSING WINDSHIELD WIPER

Abstract

A windscreen wiper or windshield wiper is a device used to remove rain and debris from a windscreen. Almost all motor vehicles, in clouding trains, aircraft and watercraft, are equipped with such wipers, which are usually an essential requirement. A wiper generally consists of an arm, pivoting at one end and with a long rubber blade attached to the other. The blade is swung back and forth over the glass, pushing water from its surface. The speed is normally adjustable, with several continuous speeds and often one or more "intermittent “settings. Most automobiles use two synchronized radial-type arms. It takes a lot of force to accelerate the wiper blades back and forth across the windshield so quickly. In order to generate this type of force, a worm gear is used on the output of a small electric motor. The worm gear reduction can multiply the torque of the motor by about 50 times, while slowing the output speed of the electric motor by 50 times as well. The output of the gear reduction operates a linkage that moves the wipers back and forth. Inside the motor/gear assembly is an electronic circuit that senses when the wipers are in their down position, they are parked at the bottom of the windshield and then cuts the power to the motor. This circuit also parks the wipers between wipes when they are on their intermittent setting. With drivers exposed to an ever-increasing number of distractions, an automatic rain-sensing wiper. Systems become an even more appealing feature, as they work to minimise the time the driver must take his/her hands off the wheel. These systems detect droplets of rain on the wind shield and automatically turn on and adjust the wiper system in accordance to the level of precipitation.