Power window

Windows are technical devices that are used to lift and lower -hung windows, car windows or other openings.

In the automotive industry

Formation

The first window in the automotive industry were fixed or plug-in, first used in the front, and later on the sides. A further development were reversible hinges on windshields. The last stage of development before the use of commonly used today power windows were hung windows ( in the side area ). An illustrative example of the use of top-hung windows is to this day driven car model Citroen 2CV Citroën with its distinctive " swinging " side windows. In addition, sliding windows were common, such as the Renault 4 folding or sliding windows have two advantages: they are more cost effective, and it can prevent water in the door. The seals in window regulators can not guarantee a perfect tightness; rather always penetrates a certain amount of water, even if only in the movement of the window in the window is wet. For this reason, must be attached to the door bottom water drains. Are these, however, blocked or is not level the vehicle accumulates there and the water can lead to corrosion.

In automotive (mechanical)

The entrepreneur Max Brose made ​​in 1928 for the first time crank window regulator. By use of the patented wrap spring 1926 is first time been possible to keep the vehicle window pane in any arbitrary position. These so-called crank sets were sold under the brand name "Atlas". Customers have included Daimler -Benz, Volkswagen and Borgward and Lloyd.

In the automobile ( electric)

In the U.S., electrically operated windows were (now in the Ford group ) was introduced to Lincoln from 1941.

The first European car with power windows was the BMW 503 from the 1950s.

Today in all vehicle classes increasingly power windows are installed. Typically, an individual switch is mounted in each door panel. Another set of buttons located in the driver's door, so that the driver can operate all windows. In some car models, the central set of keys is housed in the center console, where he is also accessible for the passenger.

Operation

With power windows, working with cables, drives an electric motor via a Schnecken-/Stirnradgetriebe to a cable drum. At this the two ends of a steel cord are mounted so that upon rotation of one end up and the other is settled. The tension cable pulls through a Bowden cable and pulleys on two guide rails running window fittings, the cable end without train is rewound onto the drum. The ends of the two Bowdenzugmäntel are resiliently held on the housing of the drive in order to bring a certain amount of resilience in the system. But there are also other systems in use.

Anti-trap

Simpler systems realize a pinch partially mechanically slip or friction clutches. For more complex or more convenient power windows with automatic closing function ( " express up", " comfort closure" etc.) it is important that a pinch (English " pinch protection" ) is available: Once the drive torque to the window closing function of the window position a certain exceeds limit, the direction of movement of the disc must be reversed to release the supposed obstacle again. Pinch protection must determine on the position of the window, if an obstacle is present or the window has reached the rubber seal on the end position. Typically, the anti-pinch function is realized by a directly attached to the engine electronics, as you position the window at the motor shaft easily be measured using Hall sensors.

In the picture can be seen on the right side of the open drive unit with drive motor and worm gear. On the axis of the front wheel sits a small drum (in the picture not visible) on which the actuating Bowden cable is wound. In the left half of the picture you can see the control electronics, which also contacts the engine and determine the window position based on the number of engine revolutions and realized the trap release.

In greenhouses, cold frames, etc.

Here purely mechanical windows are often used, usually in conjunction with hinged windows. These have a lever mechanism and may be lifted by means of rods and / or joint systems and fixed by means of pegs or slipping clutch in the desired position.

For partial automation ( on a mechanical basis ) the linkage to be moved by pistons stuck in a container filled with liquid or gas cylinder. The contents of the cylinder expands when heated and contracts when cooled, causing the piston in or out drives. This will mean that the window opens or closes in heat in cold weather.

When using electric window can eg are driven by an electric motor that raises the box via gears, and rack or lower. In such systems, all possibilities of automation can be achieved.