Steering wheel
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A steering wheel is a type of steering control used in most modern land vehicles, including all mass-production automobiles. The steering wheel is the part of the steering system that is manipulated by the driver; the rest of the steering system responds to the movements of the steering wheel. This can be through direct mechanical contact in rack and pinion steering, with the assistance of hydraulics in power steering, or in some concept cars and modern production cars such as the Toyota Prius entirely through computer control. To prevent motor vehicle theft, most steering wheels are locked if the ignition key is taken out of the ignition lock.
Remote car audio controls are generally included on the steering wheel.
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[edit] History
The first automobiles were steered with a tiller, but Packard introduced the steering wheel on the second car they built, in 1899. Within a decade, the steering wheel had entirely replaced the tiller in automobiles.
[edit] Passenger cars
Steering wheels for passenger automobiles are usually circular, the wheel being attached to the steering column by one or more spokes (though a single spoke wheel is a rather rare exception). Other types of vehicles may use the circular design, a butterfly shape, or some other shape. In countries where cars must drive on the left side of the road, the steering wheel is typically on the right side of the car; the converse applies in countries where cars drive on the right side of the road.
Besides its use in steering, the steering wheel is the usual location for a button to activate the car's horn. Additionally, many modern automobiles may have other controls, such as cruise control and audio system controls built into the steering wheel to minimize the extent to which the driver must take his hands off the wheel.
An undeployed airbag, used to protect the driver in event of a frontal collision, is mounted inside a cover in the center of the steering wheel. Therefore, to prevent injury from the airbag deployment, it is important that the driver does not sit too close. Typical recommendations are a distance of at least 1 foot (30 cm) between the surface of the airbag cover and the driver's chest.
Power steering and power assist steering both give the driver an easier means by which the steering of a car can be accomplished. Modern power steering almost universally relies on a hydraulic system. Mechanical power steering systems (ex. Studebaker, 1952) have been invented, but their weight and complexity negate the benefits that they provide.
While other methods of steering passenger cars have resulted from experiments, none have been deployed as successfully as the steering wheel.
[edit] Other designs
The steering wheel is centrally located on certain high-performance sports cars, such as the McLaren F1, and in the majority of single-seat racing cars.
As a driver may have his hands on the wheel for hours at a time, steering wheels are designed with ergonomics in mind. However, the most important concern is that the driver can effectively convey torque to the steering system; this is especially important in vehicles without power steering. A typical design for circular steering wheels is a steel wheel with a rubberized grip molded around it. Some drivers purchase steering wheel covers to enhance the grip or comfort of the wheel, or simply decoration. Another device used to make steering easier is the brodie knob.
A similar device in aircraft is the yoke. Water vessels not steered from a stern-mounted tiller are directed with the ship's wheel, which may have inspired the concept of the steering wheel.
[edit] Adjustable Steering Wheels
Originally a luxury option on cars, the tilt function helps to adjust the steering wheel by moving the wheel through an arc in an up and down motion. Tilt Steering Wheels rely upon a ratchet joint located in the steering column just below the steering wheel. By disengaging the ratchet lock, the wheel can be adjusted upward or downward while the steering column remains stationary below the joint. Some designs place the pivot slightly forward along the column, allowing for a fair amount of vertical movement of the steering wheel with little actual tilt, while other designs place the pivot almost inside the steering wheel, allowing adjustment of the angle of the steering wheel with almost no change it its height.
In contrast, an adjustable steering column allows the steering wheel height to be adjusted with only a small, useful change in tilt. Most of these systems work with compression locks or electric motors instead of ratchet mechanisms; the latter may be capable of moving to a memorized position when a given driver uses the car, or of moving up and forward for entry or exit. Many also allow adjustment in another dimension, "telescoping" toward and away from the driver.
[edit] Buttons on the Steering Wheel
Inter alia, audio system, the telephone and voice control, acoustic repetition of the last navigation instruction, infotainment system, and on board computer functions can be operated comfortably and safely using buttons on the steering wheel. This ensures a high standard of additional safety since the driver is able in this way to control and operate many systems without even taking his hands off the wheel or his eyes off the road.
The scroll buttons can be used to set volume levels or page through menus.
The buttons can be adjusted manually for reach and height.
[edit] Gaming imitations
Certain input devices (originating in arcade machines) are available for computers and console games are designed to look and feel like a steering wheel, and are intended for use in racing games. The more inexpensive ones are just paddle controllers with a larger wheel, but some go so far as to employ force feedback to simulate the tactile feedback a real driver feels from a steering wheel. This good feedback from the steering contributes to steering "feel" and is one of the hallmarks of a true "driver's car" or sports car.
[edit] Trivia
On April 1, 2005, advertisements by BMW in Britain's broadsheet press claimed that forthcoming EU legislation would prohibit the use of right-hand drive vehicles on the continent by 2008. The advertisements furthermore claimed that BMW had devised a centrally-located "no-hands drive" control system, developed by a "Dr Bitt-Fischi"; a tie-in website was located at uninventthewheel.co.uk. However, this was just an April fools day joke as stated on the website.
[edit] See also
- Steering wheel heating
