Big Round Doughnut
iPhoneOgraphy – 11 Jul 2016 (Day 193/366)
A tire (American English) or tyre (British English) is a ring-shaped vehicle component that covers the wheel’s rim to protect it and enable better vehicle performance. Most tires, such as those for automobiles and bicycles, provide traction between the vehicle and the road while providing a flexible cushion that absorbs shock.
The materials of modern pneumatic tires are synthetic rubber, natural rubber, fabric and wire, along with carbon black and other chemical compounds. They consist of a tread and a body. The tread provides traction while the body provides containment for a quantity of compressed air. Before rubber was developed, the first versions of tires were simply bands of metal fitted around wooden wheels to prevent wear and tear. Early rubber tires were solid (not pneumatic). Today, the majority of tires are pneumatic inflatable structures, comprising a doughnut-shaped body of cords and wires encased in rubber and generally filled with compressed air to form an inflatable cushion. Pneumatic tires are used on many types of vehicles, including cars, bicycles, motorcycles, buses, trucks, heavy equipment, and aircraft. Metal tires are still used on locomotives and railcars, and solid rubber (or other polymer) tires are still used in various non-automotive applications, such as some casters, carts, lawnmowers, and wheelbarrows.
Historically, the spelling was “tire” and is of French origin, which comes from the word tirer, to pull. The reason for this naming is that originally “tire” referred to iron hoops or thick wires bound to carriage wheels. In French blacksmithing the word for a drawn iron rod is a tirer, or pull.
The same word was often used for any metal drawing or rolling process. In an article in the London Magazine/Intelligencer of 1853 “The Utility of Broad Wheels,” the author explains that the common practice was to bend two rods, called “tires”, into hoops and bind them to the wheel, but it is preferable to use an iron band, called a “broad wheel” rather than the rods, because as the rods wear they bite into the wheel. Another early mention of a tire in English is in The Scots Magazine, Volume 15 By James Boswell (1753).
Another etymology of “tire” is provided by Online Etymology Dictionary, essentially that the word is a short form of “attire,” and that a wheel with a tire is a dressed wheel. Some other etymologists may share this view.
The spelling tyre does not appear until the 1840s when the English began shrink fitting railway car wheels with malleable iron. Nevertheless, traditional publishers continued using tire. The Times newspaper in Britain was still using tire as late as 1905. The spelling tyre, however, began to be commonly used in the 19th century for pneumatic tires in the UK. The 1911 edition of the Encyclopedia Britannica states that ” the spelling ‘tyre’ is not now accepted by the best English authorities, and is unrecognized in the US”, while Fowler’s Modern English Usage of 1926 says that “there is nothing to be said for ‘tyre’, which is etymologically wrong, as well as needlessly divergent from our own [sc. British] older & the present American usage”. However, over the course of the 20th century tyrebecame established as the standard British spelling.
The earliest tires were bands of leather, then iron, (later steel), placed on wooden wheels, used on carts and wagons. The tire would be heated in a forge fire, placed over the wheel and quenched, causing the metal to contract and fit tightly on the wheel. A skilled worker, known as a wheelwright, carried out this work. The outer ring served to “tie” the wheel segments together for use, providing also a wear-resistant surface to the perimeter of the wheel. The word “tire” thus emerged as a variant spelling to refer to the metal bands used to tie wheels.
The first patent for what appears to be a standard pneumatic tire appeared in 1847 lodged by the Scots inventor Robert William Thomson. However, this never went into production. The first practical pneumatic tire was made in 1888 for his son Johnnie’s tricycle, in May Street, Belfast by Scots-born John Boyd Dunlop, proprietor of one of Ireland’s most prosperous veterinary practices. It was an effort to prevent the headaches his 10-year-old son was given by jarring while riding on rough pavements. His doctor, John, later Sir John Fagan, had prescribed cycling as an exercise for the boy and, a regular visitor, Fagan participated in the development of the first pneumatic schemes. In Dunlop’s tire patent specification dated 31 October 1888 his interest is only in its use in cycles and light vehicles. In September 1890 he was made aware of an earlier development but the company kept the information to itself.
In 1892 Dunlop’s patent was declared invalid because of prior art by forgotten fellow Scot Robert William Thomson of London (patents London 1845, France 1846, USA 1847), although Dunlop is credited with “realizing rubber could withstand the wear and tear of being a tire while retaining its resilience”. John Boyd Dunlop and Harvey du Cros together worked through the ensuing considerable difficulties. They employed inventor Charles Kingston Welch and also acquired other rights and patents which allowed them some limited protection of their Pneumatic Tyre business’s position. Pneumatic Tyre would become Dunlop Rubber and Dunlop Tyres. The development of this technology hinged on myriad engineering advances.
The vulcanization of natural rubber which he patented in 1844 is credited to Charles Goodyear and Robert William Thomson.
Synthetic rubbers were invented in the laboratories of Bayer in the 1920s.
In 1946, Michelin developed the radial tire method of construction. Michelin had bought the bankrupt Citroën automobile company in 1934, so it was able to fit this new technology immediately. Because of its superiority in handling and fuel economy, use of this technology quickly spread throughout Europe and Asia. In the U.S., the outdated bias-ply tire construction persisted, with market share of 87% as late as 1967. Delay was caused by tire and automobile manufacturers in America “concerned about transition costs.” In 1968, Consumer Reports, an influential American magazine, acknowledged the superiority of radial construction, setting off a rapid decline in Michelin’s competitor technology. Even in the U.S., the radial tire now has a market share of 100%.