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Window switches with remote disable control on driver's door (1993 Jeep Grand Cherokee).

Power windows or electric windows are automobile windows which can be raised and lowered by depressing a button or switch, as opposed to using a hand-turned crank handle.

James Arthur Ward in his book, The Fall of Packard Motor Car Company states that Packard introduced the first power windows (along with automotive air-conditioning systems) in the 1940 Packard 180 series. This was a hydro-electric system and does not appear to have included power seats. In 1941, the Ford Motor Company followed quickly with power windows on the Lincoln Custom (only the limousine and seven-passenger sedans). Other information confirming this follows from [1]. Cadillac had a straight-electric divider window (but not side windows) on their series 75 limousines immediately prior to World War II.

Many advertisements use the term electric or power window "lifts" (somewhat more English) rather than merely power windows or power window assists.

Power assists originated in the need and desire to move convertible body-style tops up and down by some means other than human effort. The earliest power assists were vacuum-operated and were offered on Chrysler Corporation vehicles, particularly the low-cost Plymouth convertibles in the late 1930s.

Shortly before World War II, General Motors developed a central hydraulic pump for working convertible tops[2]. This system was introduced on 1942 convertibles built by GM. Previously, GM had used a vacuum system which did not have the power to handle increasingly larger and complex (four side-windows vs. only two) convertible top mechanisms.

Individual for front bench seats were introduced after WWII. All of these systems were based on major hydraulic advances made in military weapons (tanks, aircraft) in prepartion for World War II. The full Hydro-Lectric system (windows, front seat adjustment and convertible top) appeared in either the 1946 or 1947 model year [3]. The seat and window assists were optional on closed cars (standard on some Cadillac Series 75 models). The full system was standard only on the high-end GM convertibles made by Oldsmobile, Buick and Cadillac. It was only available as a package; that is, power assisted windows, front seat and convertible top (where applicable). It can be identified in 1948 and later General Motors model numbers with an "X" at the end, such as the 1951 Cadillac Sixty Special sedan, model 6019X [4].

Ford Motor Company (FoMoCo) products also had a similar electro-hydraulic system on higher-end convertibles (Mercury, Lincoln)by 1951[5].

A similar system was also used by other luxury car makes (Lincoln, Chrysler, Packard) until Chrysler Corporation introduced the more satisfactory all-electric operation on the 1951 Imperial. General Motors also followed with full electric operation in 1954. This included four-way and then six-way seats, which were introduced in 1956. Chevrolet introduced the oddity of power front windows (only) in the 1954 model. Ford also introduced full four-door power windows in 1954.

Electrically-operated vent windows were introduced on 1958 Cadillacs. Some luxury cars in the 1970s and 1980s had as many as fourteen switches on the driver's door for windows (four vent, four main), driver seats (three switches), power door locks, mirror adjustment, power door lock-out, cigarette lighter, and other items.

In a typical installation, there is an individual switch at each window and a set of switches in the driver's door or a-frame pillar, so the driver can operate all the windows. These switches took on many different appearances, from heavy chrome plate to inexpensive plastic.

However, some models like Saab and Holden have used switches located in the center console, where they are accessible to all the occupants. In this case, the door-mounted switches can be omitted.

Power windows are usually inoperable when the car is not running as the electrical system is not 'live' once the ignition has been turned off. The Hydro-Lectric system; however, could lower the windows at rest, since pressure from the hydraulic system was merely released to lower the window. Raising the windows required the pump to operate (at a fairly high noise level) and introduce pressure at each cylinder. These hydraulic systems also required pressure lines to each cylinder (door, seat and top) and tended to leak.

Many modern cars have a time delay feature, first introduced by Cadillac in the 1980s, called retained accessory power. This allows operation of the windows and some other accessories for ten minutes or so after the engine is stopped. Another fairly recent innovation, pioneered by Nissan at about the same time, is the express-down window, which allows the window to be fully lowered with one tap on the switch, as opposed to holding the switch down until the window retracts. Many luxury vehicles during the 1990s expanded on this feature, to include express-up on the driver's window, and recently, some manufacturers have added the feature on all window switches for all passengers convenience. This is done by activating the switch until a "click" response is felt.

Power windows have become so common that by 2008, some automakers eliminated hand cranks from all models. So many vehicles have power windows that some people no longer understand the (formerly) common sign from another driver of using their hand to simulate moving a window crank to indicate that they wish to speak with someone (stopped at a light or in a parking lot).

Power windows have come under some scrutiny after several fatal accidents in which children's necks have become trapped, leading to suffocation. Some designs place the switch in a location on a hand rest where it can be accidentally triggered by a child climbing to place his or her head out of the window. To prevent this, many vehicles feature a driver-controlled lockout switch, preventing rear-seat passengers (usually smaller children) from accidentally triggering the switches. This also prevents children from using them as toys and pets riding with their heads out windows from activating the power window switch.

Starting with the 2008 model year, U.S. government regulations required automakers to install power window controls that are less likely to be accidentally activated by children.[6] However, the rules do not prevent all potential injuries to a hand, finger, or even a child's head, if someone holds the switch when the window is closing. In 2009, the U.S. auto safety administration tentatively decided against requiring all cars to have automatic reversing power windows if they sense an obstruction while closing.[7] Proposed requirements concern "one-touch" up window systems, but most vehicles with this feature already have automatic-reversing.[8]

References

  1. ^ Hemmings Classic Cars (magazine), Jim Donelly column, August, 2008 and Letter to the Editor, November 2008
  2. ^ Collectible Automobile, June 2008, p. 14
  3. ^ See "How Things Work, website shown below
  4. ^ Cadillac, The Complete History, Maurice Hendry, 1975
  5. ^ Hemmings Classic Car, January 2009, pps. 22-23
  6. ^ Hyde, Justin. "Power Window Evolves: Cars will get pull switches for safety" Detroit Free Press 2006-04-15, retrieved on 2009-09-21.
  7. ^ Manning, Stephen "Safety agency: Reversible auto windows unnecessary" Associated Press, 2009-08-28, retrieved on 2009-09-21.
  8. ^ Shepardson, David "NHTSA: Automatic reversing windows unnecessary" Detroit News 2009-08-28 , retrieved on 2009-09-21.

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