windshield wipers
.jpg)
A windshield wiper is a device for cleaning the front or rear window of a motor vehicle , aircraft , ship or rail vehicle . Windshield wipers consist of a wiper arm , wiper blade and drive. The wiper blade is equipped with a rubber profile that pushes unwanted moisture or dirt off the windshield and gives the vehicle occupants a better view of the outside world.
In the event of heavy or dried-on dirt, the windscreen is moistened with windscreen washer fluid from the windscreen washer system .
construction
Conventional windshield wipers consist of a metal wiper arm that is attached to the wiper shaft. A hinge enables the windscreen wiper to be folded away from the window. For the flat windows of the automobiles of earlier generations, a rigid metal rail with a rubber profile was enough as a wiper blade . For the curved vehicle windows customary today, manufacturers have divided the wiper blade into several parts with joints that press the rubber profile against the window. Two thin, elastic metal inserts in the rubber profile ensure that the contact pressure is evenly distributed. In addition, there are non-segmented flat wiper blades (also called aero wipers) on the market.
drive
Windshield wipers are usually powered by one or more electric motors. A common design - especially in vehicles of the lower vehicle classes - is a rotating electric motor with only one direction of rotation, which generates the wiping movement via a lever mechanism (so-called "rotary motor").
There are also windshield wipers with reversing motors, especially in vehicles in the upper vehicle classes. These motors are generally more expensive than those that work on the rotary principle. The alternating direction of rotation for the back and forth movement requires special control electronics for the electric motor. This technology has been used in the VW Touran since 2003, for example . On its windshield, two opposing wipers are driven by mechanically independent motors controlled via the LIN bus . No connecting rods are necessary. In addition, a wiper with a reversing motor is able to change direction at any position of the window when it is blocked (e.g. by snow).
Some commercial vehicles have wiper systems with pneumatic drive. For example, the windshield wipers on the 420 series suburban trains are operated with compressed air. They can each be controlled individually and some have no fixed parking position. It is much more a question of the operator's “ability” to determine where the windshield wiper is located. If it should be in the field of view, a small amount of compressed air has to be fed in again so that it slides a little further.
Load sharing
The whippletree mechanism uses a tree-like structure to ensure a more even distribution of the pressure on the windshield.
arrangement
Synchronous wipers, common design in cars
Synchronous wipers, mirrored, e.g. E.g .: Mercedes-Benz W 140 , Fiat 850
Opposing wipers, e.g. E.g .: Mercedes-Benz W 115 , VW Sharan , Opel GT
Opposing wipers, Seat Altea resting on top
Single lever wiper, single arm wiper z. E.g .: Renault Twingo I, Citroën CX
Single lever wiper with lift control, e.g. E.g .: Mercedes-Benz W 124
Parallelogram wiper, pantograph wiper z. E.g .: standard bus , MAN gl , Porsche 904 (single wiper)
Triple wiper, truck, e.g. E.g .: MAN , Morgan Aero 8
Two independent wipers on split windows (obsolete), e.g. E.g .: Magirus-Deutz round hood
Two independent wipers on split windows, hanging (obsolete) e.g. B. Hummer H1
In addition to the conventional arrangement of two equally large, mostly standing wipers (axis below the window), there are solutions with a hanging arrangement and with three wipers for wide windows or even a single so-called single-arm wiper that covers large, flat windows. Two wipers of different sizes are also used for such front windows. Technically complex are parallelogram or double-arm windshield wipers with a always vertical wiper blade, which on the one hand hardly disturbs the air flow and on the other hand, for example, cleans the large front windows of buses at almost the same height almost up to the frame.
In order to improve the aerodynamics or the drag coefficient of vehicle bodies, since the beginning of the 1980s the wiper arms on many vehicles have been installed under a lowered windshield in such a way that in the starting position they are wholly or at least partially below the rear edge of the bonnet and no or only a small amount Cause air turbulence . Opel Kapitän , Admiral and Diplomat had such sunken windshield wipers as early as 1969. Since the late 1990s, windshield wiper arms that have not been concealed have been found again in small cars such as the Smart , the Twingo and the Mini .
Another design are counter-rotating wipers. In the Seat Altea, for example, the wiper blades are in the rest position under the cover of the A-pillar.
Opposing windshield wipers in the A-pillar
Parallelogram wiper on the bus
... and on the Porsche 904
Slinger and linear wiper on a ship
Windshield wipers of the ICE 3
.jpg)
A special method of removing rain from windows is the sling disc used on ships . Another type of ship used are linear windshield wipers. The wipers run back and forth in a rail above the windows and wipe the entire surface.
service
In most modern car models, the windscreen wiper motor is switched with a lever on the steering column, a so-called steering column switch , or via a control satellite .
The drive can be interrupted by an interval switch so that the windshield wiper does not rub against the windshield in light rain or snowfall - "to run dry" . There are also rain sensors that are supposed to detect how much the windshield is wetted by rain or snow and that control the use of the windscreen wipers according to the measurement result.
history
The first draft of a windshield wiper is attributed to the Polish concert pianist Józef Hofmann . Mills Munitions from Birmingham was the first to receive an English patent for it. At about the same time in 1903, three inventors applied for automotive window cleaning patents, namely Mary Anderson, Robert Douglass, and John Apjohn. In November 1903, the American Mary Anderson received the patent for the world's first working windshield wiper. The patent (US 743,801) was handed over to her on November 10, 1903 by the US Patent Office . Anderson's device was operated by hand and consisted of a lever attached near the steering wheel, with which the driver could set a spring-loaded swing arm with a rubber blade on the windshield in motion, which then returned to its starting position.
In 1905 Heinrich von Prussia , brother of Kaiser Wilhelm II , was the first German to apply for a patent for such a system . On March 24, 1908, he received the patent for it. At the time he drove an Opel . The windshield wiper was also hand operated.
In 1926, the Bosch company first presented a device in which an electric motor made a wiper arm with a rubber lip swing over the car window in order to push away the rainwater. Until then, cars had, if at all, a manually operated "scraper ruler" or wipers with mechanical or "vacuum" drives with the major disadvantage that when driving slowly or even when waiting at a traffic light, the wiper slowly or not at all moved more and therefore the driver had to crank it by hand.
In the decades that followed, the electric motor prevailed as a wiper drive as far as possible, even if, for cost reasons, the cam or speedometer shaft with a clutch and a reduction gear was used in some models until the 1960s .
In 1964, Robert Kearns , professor of engineering at Wayne State University , invented the interval wiper. With his invention, Kearns followed the human eyelid , which automatically closes and opens again in an interval of a few seconds. Before he received the first of over 30 patents in 1967, he proposed the model to the automaker Ford Motor Company . However, from 1969 onwards he built his own interval windscreen wiper systems without Kearns sharing the profit. Other automakers followed within a few years. Kearns filed a patent infringement lawsuit against Ford and 26 other automakers. In 1990 he refused a settlement with Ford and went on to sue. In July 1990, a federal court closed the case and ordered Ford to pay $ 10.2 million for accidental patent infringement. In December of that year, Chrysler was convicted of paying $ 20 million.
In 1999, Robert Bosch GmbH first launched the jointless flat bar wiper (Aerotwin) on the market, which is now available on almost all new vehicles.
Others
The German artist Herbert Zangs (1924–2003) used windshield wipers, among other things, to apply paint.
Web links
- Mary Anderson patent specification (PDF file; 115 kB)
- Patent specification Heinrich von Prussia (PDF file; 167 kB)
- Bosch patent specification (PDF file; 69 kB)
Individual evidence
- ↑ Compressed air wipers in the 420 series in action (13min 25s)
- ↑ http://historygarage.com/inventor-windshield-wiper-historys-battle-title
- ↑ https://www.express.co.uk/life-style/cars/613310/Where-would-we-be-without-windscreen-wipers
- ^ Inventor of the Week Archive. Windshield wiper. Massachusetts Institute of Technology, September 2011, accessed June 13, 2013 .
- ↑ Mary Anderson. Encyclopedia of Alabama, March 9, 2010, accessed June 13, 2013 .
- ↑ Window-Cleaning Device ( English ) United States Patent and Trademark Office. Retrieved October 19, 2013.
- ↑ Prince Heinrich of Prussia - the tinkerer from the Alumni magazine of the Technical University of Berlin 3rd volume · No. 5 · December 2001 ( Memento from April 18, 2007 in the Internet Archive ) (PDF; 157 kB)
- ↑ Jürgen Pander: Windshield wiper quiz: What is there scrubbing? Spiegel.de, accessed on June 13, 2013 .
- ↑ a b c Matt Schudel: Accomplished, Frustrated Inventor Dies (English) . In: Washington Post , February 26, 2005. Retrieved June 13, 2013.