Steering wheel
A steering wheel is a type of steering control in vehicles.
Steering wheels are used in most modern land vehicles, including all mass-production automobiles, buses, light and heavy trucks, as well as tractors and tanks. The steering wheel is the part of the steering system that the driver manipulates; the rest of the steering system responds to such driver inputs. This can be through direct mechanical contact as in recirculating ball or rack and pinion steering gears, without or with the assistance of hydraulic power steering, HPS, or as in some modern production cars with the help of computer-controlled motors, known as electric power steering.
History
Near the start of the 18th century, many sea vessels appeared using the ship's wheel design. However, historians are unclear when that approach to steering was first used. The first automobiles were steered with a tiller, but in 1894, Alfred Vacheron took part in the Paris–Rouen race with a Panhard 4 hp model which he had fitted with a steering wheel. That is believed to be one of the earliest employments of the principle.From 1898, the Panhard et Levassor cars were equipped as standard with steering wheels. Charles Rolls introduced the first car in Britain fitted with a steering wheel when he imported a 6 hp Panhard from France in 1898. Arthur Constantin Krebs replaced the tiller with an inclined steering wheel for the Panhard car he designed for the 1898 Paris–Amsterdam–Paris race which ran 7–13 July 1898.
In 1898, Thomas B. Jeffery and his son, Charles T. Jeffery, developed two advanced experimental cars featuring a front-mounted engine and a steering wheel mounted on the left-hand side. However, the early automaker adopted a more "conventional" rear-engine and tiller-steering layout for its first mass-produced Ramblers in 1902. The following year, the Rambler Model E was largely unchanged, except that it came equipped with a tiller early in the year that was changed to a steering wheel by the end of 1903. By 1904, all Ramblers featured steering wheels. Within a decade, the steering wheel had entirely replaced the tiller in automobiles.
At the insistence of Thomas B. Jeffery, the driver's position was also moved to the left-hand side of the car during the 1903 Rambler production. Most other car makers began offering cars with left-hand drive in 1910. Soon after, most cars in the US converted to left-hand drive.
Passenger cars
Steering wheels for passenger automobiles are generally circular. They are mounted to the steering column by a hub connected to the outer ring of the steering wheel by one or more spokes. Other types of vehicles may use a modified circular design, a butterfly shape, or some other shape, such as a yoke. On some Tesla models, the steering control is through a yoke rectangle shaped with rounded edges and two pistol grips. The C8 Corvette includes a square-type steering wheel with rounded corners, described as a 'squircle'. The objective of the flat bottom is to ease diver egress while the flattened top enhances the line of sight when driving. General Motors applied for a US patent for a modular steering control that can be updated with components or changed in shape ranging from a traditional circle to a yoke.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.
In addition to its use in steering, the steering wheel is the usual location for a button to activate the car's horn. Modern automobiles may have other controls, such as cruise control, audio system, and telephone controls, as well as paddle-shifters, built into the steering wheel to minimize the extent to which the driver must take their hands off the wheel.
The steering wheels were rigid and mounted on non-collapsible steering columns. This arrangement increased the risk of impaling the driver in case of a severe crash. The first collapsible steering column was invented in 1934 but was never successfully marketed. By 1956, Ford came out with a safety steering wheel that was set high above the post with spokes that would flex, but the column was still rigid. In 1968, United States regulations were implemented concerning the acceptable rearward movement of the steering wheel in case of a crash. Collapsible steering columns were required to meet that standard. Before this invention, the Citroën DS incorporated a curved and off-center single-spoke steering wheel designed to deflect the driver from the steering column in case of a crash.
Power steering affords the driver reduced effort to steer the car. Modern power steering has almost universally relied on a hydraulic system, although electrical systems are steadily replacing this technology. Mechanical power steering systems were introduced, such as on 1953 Studebakers. However, hydraulically assisted systems have prevailed.
While other methods of steering passenger cars have resulted from experiments, for example, the "wrist-twist" steering of the 1965 Mercury Park Lane concept car was controlled by two rings, none have yet been deployed as successfully as the conventional large steering wheel.
Passenger automobile regulations implemented by the U.S. Department of Transportation required the locking of steering wheel rotation to hinder motor vehicle theft; in most vehicles, this is accomplished when the ignition key is removed from the ignition lock. See steering lock.
Other designs
The driver's seat and steering wheel are centrally located on certain high-performance sports cars, such as the McLaren F1, and most single-seat racing cars.As drivers may continuously have their hands on the steering wheel for many hours, these are designed with ergonomics in mind. However, the most crucial concern is that the driver can effectively convey torque to the steering system, especially in vehicles without power steering or in the rare event of a loss of steering assist. A typical design for circular steering wheels is a steel or magnesium rim with a plastic or rubberized grip molded over and around it. Some drivers purchase vinyl or textile steering wheel covers to enhance grip and comfort or simply as 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. The steering wheel is better than other user interfaces and has persisted because driving requires precise feedback that is provided by a large interface.
Early Formula One cars used steering wheels taken directly from road cars. They were normally made from wood. Without interior cabin packaging constraints, they tended to be made as large a diameter as possible to reduce the effort needed to turn. As cars grew progressively lower and driver's areas more compact throughout the 1960s and 1970s, steering wheels became smaller to fit into the interior space.
Spokes in steering wheel
The number of spokes in the steering wheel has continuously changed. Most early cars had four-spoke steering wheels.A Banjo steering wheel was an option in early automobiles. They predate power steering. The wire spokes were a buffer or absorber between the driver's hands and the vibration transmitted from the road surfaces. Most were three- or four-spokes made of four or five wires in each spoke, hence the name "Banjo".