Windshield 254664 226022728 2008-07-16T14:07:05Z Dnomyar34 889738 /* External links */ {{Otheruses4|glass used on vehicles|the microphone wind protecting accessory|microphone}} {{refimprove|date=March 2008}} [[image:Panoramic-windshield.JPG|right|thumb|Panoramic (wrap-around) windshield on a 1959 Edsel Corsair.]] The '''windshield''' or '''windscreen''' of an [[aircraft]], [[automobile]], [[bus]], [[motorcycle]], or [[tram]] is the front [[window]]. Modern windshields are generally made of [[Laminated glass|laminated safety glass]], a type of treated glass, which consists of two (typically) curved sheets of [[glass]] with a [[plastic]] layer [[laminate]]d between them for safety, and are [[Polyurethane|glue]]d into the window frame. Motorcycle windshields are often made of high-impact [[Polymethyl methacrylate|acrylic plastic]]. As the name implies, their main function is to shield the driver from the wind, though they do not do so as totally as those of a car. ==Usage== In daily use, windshields mainly protect the vehicle's occupants from [[wind]], [[temperature]] extremes, and flying [[debris]] such as [[dust]], [[insect]]s, and [[Rock (geology)|rocks]], as well as providing an [[aerodynamics|aerodynamically]] formed window towards the front. [[UV Coating]] may be applied to screen out harmful [[ultraviolet]] light. ==Safety== Early windshields were made of ordinary window glass, but that could lead to serious injuries in the event of a crash. They were replaced with windshields made of [[toughened glass]] and were fitted in the frame using a [[rubber]] or [[neoprene]] [[Seal (mechanical)|seal]]. The hardened glass shattered into many mostly harmless fragments when the windshield broke. These windshields, however, could shatter from a simple stone chip. In 1919, [[Henry Ford]] solved the problem of flying debris by using a new technology founded in France called [[laminated glass|glass laminating]]. Windshields made using this process were actually two layers of glass with a cellulose inner layer. This inner layer held the glass together when it fractured. Between 1919 and 1929, Ford ordered the use of laminated glass on all of his vehicles.<ref>[http://www.glass.org/consumer/a_windshield.htm] National Glass Association - "Your Windshield is Not Just a "Wind-Shield" Any More"</ref> [[image:Raked_windshield_1952_DeSoto.jpg|left|thumb|Split and raked windshield on a 1952 DeSoto. Note the panes of glass are flat.]] The modern, glued-in glass contribute to the vehicle's rigidity, but the main force in innovating the windshield has historically been the need to prevent injury from sharp glass fragments. Modern windshields, now almost universally required in all nations, do not fragment, but tend to stay in one piece even if broken, except if pierced locally by a strong force. Properly installed automobile windshields are also essential to safety; along with the roof of the car, they provide protection in the case of a roll-over accident in the vehicle. ==Other aspects== In many places, laws restrict the use of heavily [[Window tinting|tinted glass]] in vehicle windshields; generally, laws specify the maximum level of tint permitted. Some vehicles have noticeably more tint in the uppermost part of the windshield of motor vehicles that blocks [[light pollution#glare|glare]] from the sun. In aircraft windshields, a current is applied through a conducting layer of [[tin|tin(IV)]] [[oxide]] to generate [[heat]] to prevent [[frost|icing]]. A similar system for automobile windshields, introduced on [[Ford Motor Company|Ford]] vehicles as "[[Quickclear]]" in Europe ("InstaClear" in North America) in the 1980s, uses very thin heating wires or conductive-film layer embedded between the two laminations. Using thermal glass has one downside: it prevents some [[Automotive_navigation_system|navigation systems]] from functioning correctly, as the embedded metal blocks the satellite signal. This can be resolved by using an external antenna for the navigation system. [[Image:Windshield-spiderweb.jpg|thumb|Automobile windshield displaying "spiderweb" cracking typical of laminated safety glass.]] ==Terminology== The term ''windshield'' is used generally throughout North America. The term ''windscreen'' is the usual term in the UK and Australia/New Zealand for all vehicles. In [[wasei-eigo|Japanese English]], it is called "front glass". In the USA, ''windscreen'' refers to the mesh or foam screen placed over a [[microphone]] to minimize wind noise, while a ''windshield'' refers to the front window of a car. In the UK, the meaning of these terms is reversed. Today’s windshields are a safety device just like seat belts and air bags. The installation of the auto glass is done with an automotive grade urethane designed specifically for automobiles. The adhesive creates a molecular bond between the glass and the vehicle. If the adhesive bond fails at any point on the glass it can reduce the effectiveness of the air bag and substantially compromise the structural integrity of the roof. (Raymond Clough) [[Image:BrooklandsGoggles.jpg|thumb|Brookland aeroscreen on a 1931 [[Austin Seven]] Sports.]] Auto windshields less than 20 [[metre|cm]] (8 inches) in height are sometimes known as '''aeroscreens''' since they only deflect the wind. The twin aeroscreen setup (often called [[Brooklands]]) was popular among older sports and modern cars in vintage style. A ''wiperless windshield'' is a windshield that uses a mechanism other than [[windshield wiper|wiper]]s to remove snow and rain from the windshield. The concept car [[Acura TL]] features a wiperless windshield using a series of jet [[nozzle]]s in the [[cowling|cowl]] to blow [[Pressure|pressurized air]] onto the windshield. ==Stone chip and crack damage== Many types of stone damage can be successfully repaired. Bullseyes, cracks, starbreaks or a combination of all three, can be repaired without removing the glass, eliminating the risk of leaking or bonding problems sometimes associated with replacement. ==Repair== Windshield repair is a process that combines modern technology and skill to fill a damaged area on a windshield with special clear adhesive resin. The resin is then cured with an ultraviolet light. When done properly, the damaged area’s strength is restored, as is most of the clarity.<p>When repairing a windshield, it is important to start with a clean work area. Any dust, dirt, or contaminants in or on the glass can result in scarring or trapped particles that will permanently be visible in the final repair. Any moisture can cause future cracks when the glass cools or heats. Many chips in automotive safety glass will never grow but insurance companies in the United States often waive the deductible to ensure they do not have to pay for the replacement of the auto glass. ==References== {{reflist}} ==See also== * [[Windshield wiper]] * [[Motorcycle windshield]] ==External links== * [http://windshields.com/ Windshields.com] An online provider of windshield repair information and companies. * [http://www.carwindshields.info/ Car Windshields] A website devoted to windshields, including markings. * [http://www.oncallwindshieldrepair.com/process-largecrack.html/ Long crack repair] A video of the crack repair process. * [http://www.glass.org] National Glass Association * [http://www.agrss.org] Auto Glass Replacement Saftey Standards Council * [http://www.raymondclough.com/ase] Auto Safety Expert {{CarDesign nav}} [[Category:Auto parts]] [[Category:Glass applications]] [[Category:Automotive safety technologies]] [[Category:Car windows]] [[de:Windschutzscheibe]] [[el:Παρμπρίζ]] [[es:Parabrisas]] [[fr:Pare-brise]] [[it:Parabrezza]] [[pt:Pára-brisas]] [[sv:Vindruta]] [[zh:擋風玻璃]]