Windscreen Wiper System

Windscreen Wiper working principle

Windscreen wiper is a device that cleans water, snow or mud from the windscreen of vehicle. Thus, it ensures proper visibility of the road ahead.  This system finds application on a large variety of locomotives from vehicles, railways to aero-planes. Generally, the term ‘windscreen wiper’ refers to the wipers installed on the front windshield of a vehicle. However, nowadays, rear wipers are also getting popular.
Almost all the modern wiper mechanisms employ an electric motor for their operation. However, in some cases, pneumatic drives are also used to drive wiper arm. Some of the primitive designs of the wiper mechanism were hand operated. A rain sensing wiper is a recent development in wipers.

Innovation: The credit of inventing windscreen wiper goes to an American inventor Mary Anderson. She invented first operational wiper in the year 1903. In her patent, she termed wiper as a ‘window cleaning device’. Prior to that, drivers used to clean the windshield manually by getting out of the car.

Various components of windscreen wiper system: Wiper mechanism comprises of the following major components:

Wiper motor: It drives the linkages of wiper mechanism which ultimately makes the wiper blade to move on the windscreen.

Linkage: Linkage performs two major functions. Firstly, it holds the wiper arm and blade in position and maintains proper contact between the blade and the windscreen. Secondly, it converts the rotary motion obtained from the motor into suitable form. And to do this, it employs a worm gear. Worm gear reduces the speed of output shaft of motor and converts it into suitable torque required to operate wiper arm.

Wiper arm: Wiper arm is the connecting link between wiper linkage and wiper blade.

Wiper blade: Blade is a rubber part that comes in contact with glass. It also has a metal clamping attached to it which aids in maintaining uniform pressure on the blade.

Windscreen wiper care tips:

1. Always clean the wiper blades before going out in a car.

2. If the vehicle is to be parked in open for a long time, lift the wiper arm so that contact between wiper blade and windscreen will be avoided. This practice helps to reduce the hardening of rubber blade due to the contact of warm windscreen.

3. Replace the damaged or hardened wiper blades immediately.