Windscreen Wipers
Windscreen wipers are a device used to remove rain, snow, ice, and debris from a windscreen or windshield. Almost all vehicles are equipped with them, since this is usually a legal requirement. A wiper generally consists of a metal arm pivoting at one end. It also has a long rubber blade attached to the other.
The arm is powered by a motor, often an electric motor, although, pneumatic power is also used in some vehicles.
The window screen wiper moves left and right pushing anything on the windshield away from blocking the driver’s view. The blade is swung back and forth over the glass. This pushes water or other precipitation from its surface. The speed is normally adjustable, with several continuous speeds and often one or more “intermittent” settings being used.
Most vehicles use two synchronized radial type arms. This is in contrast to some commercial vehicles that use one or more pantograph arms. On some vehicles, a windscreen washer system is also used. This system sprays water or an antifreeze window washer fluid at the windshield, and uses several nozzles. The windshield washer system helps to remove dirt or dust from the windshield when in concert with the wiper blades.
When antifreeze windshield washer fluid is used, it can help the wipers remove snow or ice. For winter conditions some vehicles also have additional heaters. They are aimed at the windows or embedded heating wire in the glass. The defroster system help to keep snow and ice from building up on the windshield. In rare cases, miniature wipers are installed on headlights. This is to ensure that they are functioning optimally.
Rain-sensing wipers
Some vehicles are now available with automatic wipers. They are capable of detecting the presence and amount of rain. They use a rain sensor to do this. The sensor automatically adjusts the speed and frequency of the blades according to the amount of rain detected. These controls usually have a manual override.