What happens in the background: How windows on a car work?

Most of us own cars these days. We often open and close the windows on our cars for various purposes. Do you know what happens in the background to open and close the window? Here is the description about what happens in the background

Before going to know about window mechanism, lets know how glass entered into automobile.

When automobile was invented, It didn't had a closed body. The drivers had nothing to protect them from the dust, bugs and a face full of mud while driving the car. So, this is when a windshield came into existence. It was around the early 1900's when the windshield was introduced.

The first windshields were two-piece affairs, when mud, rain, or other substances blocked his or her view forward, a driver could simply tip the top half down for an unobstructed view. While the usefulness of windshields was clear to everybody, they posed a serious danger. Manufacturers quickly discovered that during an accident, their glass windshields could shatter, sending a shower of sharp shards into the vehicle. Glass windshields proved most hazardous during front-end collisions, when passengers could end up smashing headlong through the glass.

Here is a picture to help you understand

Later changes

when the first cars with glass on all four sides were introduced, many people were afraid to ride in them. In early 20th century, two European scientists independently invented a solution to deadly windshields. While working in his lab, French scientist Edouard Benedictus accidentally knocked a flask to the floor. To his amazement, the glass did not break. Looking closer, he discovered that the chemical that had been inside the flask, nitrocellulose, had dried up, leaving an adhesive film that kept the numerous bits of fragmented glass from separating. Benedictus went on to develop a window consisting of two layers of plate glass held together by layer of cellulose.

After windshield was developed, there were cars with no windows on sides. Like the one below.

Later the car had windows on all sides.Different window styles were opted by various manufacturers for their car models. Some used fixed windows, some used horizontal sliding windows, Opera windows.

Finally in 1948 the crank windows were introduced. These are outdated now as most of the cars are coming with power windows, although low end models of some cars are still using this feature.

The first thing that lies beneath your car window is a window regulator. The window regulator is the component inside your door panel that allows you to raise or lower your window glass. Both manual and electric car windows have window regulators. A manual window is operated by a hand-crank, while an electric window is controlled by a switch or button that activates a motor.

A manual window regulator is the most basic of window lifting mechanisms. It has crank handle sticking through the door panel that regulates the up and down motion of the glass window. Humans power this type of regulator by their wrist, as the window crank needs to be physically rotated to raise and lower the door glass.

When we rotate the crank, we actually rotate a pinion which is engaged to a larger gear, which is inturn connected to the window regulator that moves your window up and down. It converts rotary motion to linear motion.

In power windows we have a motor to which we supply power from battery. When we press the power button to lift window we actually make circuit and current flows to motor. The motor is attached to a worm gear and several other spur gearsto create a large gear reduction and provides enough torque to lift the window.

In power windows we have three kinds of mechanisms. They are:

1. The Scissors Mechanism

The scissor type window regulator basically look like a giant pair of scissors. As they expand, the window goes up. When they contract, the window glass rolls down. The drawback of this type of regulator is that the wheels on the ends of them wear out over time, and break off. This causes your door glass to tilt sideways, and eventually fall down into the door. They also wear out at the center of the scissor mechanism and become noisy, sloppy, and unpredictable.

2. The Cable Mechanism

The cable type window regulator is a more modern design that is used in a huge variety of vehicles. They use far less space inside the door. Being more complicated than the scissor-type, these window regulators have more opportunity to break. The pulleys and cables in these regulators typically wear out, and snap. When that happens, the glass almost always falls inside the door, leaving your interior open.

3. The Flexible Drive Mechanism

This window mechanism was used for the rear doors in Reliant and Sundance 4-door models. The mechanism was a rack-and-pinion gear set made of tough injection-molded Delrin plastic. The Delrin rack gear was flexible and slides along a T-shaped steel track to move the glass up or down as the window crank turns the pinion gear. The window glass was fastened to the sliding rack gear by a link. A small fixed window was used in the door behind the sliding glass with this mechanism.