DEVELOPMENT OF PNEUMATIC TIRES
We have seen the development of pneumatic tire from a crude condition to a product of precision with incredibly low tolerances. It took a longtime to develop to the present level. The changes came gradually.
Let us go through the high points of development till it became an ideal product for transportation. Horse-drawn carriages required strong wheels.
Roads were of varying nature like hard earth, stone, or even unpaved fields only wood or metal wheels could stand up to these harsh conditions which was also not a comfortable ride. The earliest efforts to make them comfortable was with bands of leather, then iron, (later steel), placed on wooden wheels. The iron or steel will be made as a circular ring and then 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.
It will be interesting to know that Christopher Coloumbus on his first voyage discovered America. In his second voyage (1493- 1496), he found rubber in tropical South America. He saw Haiti inhabitants playing games with a ball made out of secretion of a tree and the bouncing nature of it made him to procure few and bring along with him. The subsequent knowledge about rubber comes from the documentary evidence, available regarding Spanish troops. Nay back in 1615 they were using them to coat on the clothes to use them as a rain protective garment 'Guayule Shrub‘ was probably the first known source of rubbers.
Charles de la Condamine first described Hevea Brasiliensis tree as the source of rubber in 1751. He found it in the Amazon forests in 1736 during his visit to South America as a member of a party sent by the Academides Sciences on Scientific expedition. A material which was originally called 'ule‘ got its name ‘Rubber' from Priestly as he used them to rub out black lead pencil marks out of paper. This was in year 1?7D and commercial sale of rubber in small cubes in London and Paris started in 1772.
All this period, rubber was not taken very seriously. Certain discoveries in the 19th century were responsible for its present position. In 1820, an
Englishman Thomas Hancock invented a masticator which helped to soften, mix and shape the rubber. The softened rubber was used for making water proof garments by Charles Mackintosh. The accidental invention of vulcanization by Charles Goodyear in rubber industry. Till quality depending upon used to make it soft and Goodyear observed that gave it stability and1839 laid the real foundation for the then rubber was found to be varying in the weather conditions. Hot conditions in cold weather it used to become stiff-rubber and sulphur mixture when heated elasticity. Goodyear took a patent for this process in 1841. This was improved by Hancock who also took a patent in 1843. The whole process was given the name of Vulcanisation after the Greek God of fire (Vulca). Almost at the same period, pneumatic tire was also invented. Invention by a Scotsman called Thomson in 1845 was not taken up seriously by any one. A veterinary surgeon of Belfast J.B. Dunlop re-invented pneumatic tyre and patented it in the year 1888.
Early rubber tires were solid (not pneumatic). Now 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 bicycles, motor cycle, cars, buses, trucks, heavy equipment and aircraft.
Metal tires are still used on locomotives and railcars, and solid rubber (or other polymer) tires are used in various non-automotive applications, such as some casters, carts, lawnmowers, and wheelbarrows.
As we mentioned above in 1839 Charles Goodyear perfected the vulcanization process of rubber by changing the physical through application of sulfur and heat in the U.S. Some time, later, Thomas Hancock, who was conducting similar research in England, met with similar success. The term vulcanization is derived from the name of the Roman god of fire This stabilization made the rubber tire practical.
The first patent for what appears to be a standard pneumatic tire appeared in 1847 lodged by the Scottish inventor Robert William Thomson. However, this never went into production.
Coincidentally, the automobile industry was born around this same time.
The first practical pneumatic tire was made in 1888 on May Street, Belfast, by Scots-born John Boyd Dunlop, owner of one of Ireland's most prosperous veterinary practices.
In 1892, Dunlop's patent was declared invalid because of prior registered patent 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 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, as well as by the development of the "clincher" rim for holding the tire in place laterally on the wheel rim.
The early tires were permanently mounted to their wheels. When a solid rubber tire wore out, the entire assembly was replaced. The bigger issue arose with pneumatic tires, as it was a difficult and time-consuming process to make a repair.
First to develop a detachable pneumatic tire was Charles K. Welch, who was ahead of others working on similar refinements. William K. Bartlett of North British Rubber Co. patented a similar tire just five weeks later.
Mr. Bartlett got the jump on competitors merely by broadening an earlier patent application for a detachable non-pneumatic tire to include pneumatic construction as well. The Bartlett "clincher tire" subsequently became the first detachable pneumatic tire introduced to the market.
Michelin also patents detachable tire, 1891. Group Michelin's earliest contact with the pneumatic tire occurred in 1889, when a stranded British cyclist sought the help of brothers Edouard and Andre Michelin in fixing his bicycle's two flat tires. The Michelins, who ran a metal, leather and rubber fabricating business at that time, perceived a need for and soon developed and patented their own version of the detachable tire. This marked the firm's entry into tire manufacturing, which later became its primary business.
The earliest tire valves provided for easy inflation but not deflation. So, inventor Charles H. Woods improved it in 1891 and developed a valve that facilitated both operations. His two-way valve became standard in Great Britain and elsewhere and remains in use for bicycle tires in some parts of the world.
Beaded-edge tire debuts in U.S., 1892. This version of the beaded-edge tire was produced by Gormully & Jeffrey Manufacturing Co., a Chicago-based bicycle manufacturer and forerunner of American Motors Corp.
Pneumatic auto tires introduced, 1895. Developed by Michelin co-founder Edouard Michelin, the air-inflated tires were demonstrated in an auto race from Paris to Bordeaux. The car was driven by his brother and company co-founder Andre Michelin, because none of the other drivers would take the presumed risk. The tires proved so troublesome that the car finished no higher than ninth, prompting a winning competitor to predict that pneumatics would "never be of use on cars." Undaunted, the brothers went on to produce and market pneumatic auto tires in 1896.
Firestone, Goodyear and another two competitors, General Tire and BF Goodrich was originally based in Akron, Ohio. Goodrich founded on August 3, 1900, the company initiated operations with twelve employees. Firestone and Goodyear were the largest suppliers of automotive tires in North America for over 75 years. In 1906 Henry Ford chose Firestone for Model T original equipment tires.
Cleveland vehicle manufacturer Alexander Winton commissioned a set of pneumatic automobile tires from the B.F. Goodrich Rubber Co., then an industrial rubber products maker in nearby Akron. The rubber company's subsequent financial success with pneumatic auto tires spawned a crowd of new Akron-based tire-making competitors.
Prior to the invention of the curing press, most pneumatic tires were vulcanized with open steam in autoclaves after being placed in ring-shaped molds and held in place by a wrapping of canvas bandage.
The Doughty press was invented by H.J. Doughty of the U.S. It used mechanical means of supporting the tire from the inside and applying a thrust to cause it to fill the mold and thereby receive an impression. Curing presses made it easier to produce elaborate tread patterns and sidewall markings as part of the vulcanizing process.
Schrader valve patented, 1898. Invented by George H. Schrader, founder of Schrader Automotive Inc., the improved valve featured an internal screw thread to facilitate a replaceable valve core. Ultimately, it became standard throughout the U.S. and elsewhere.
Rubber tires were originally smooth outer surface, as there was no inherent demand for a tread pattern (except for decorative or marketing purposes). As roadways improved and speeds increased, and as cars, unlike bikes, were used year-round in all kinds of weather, the need for better traction arose. In 1904, Continental Tire of Germany was the first to introduce a tread pattern on a tire. Grooved tires to help with traction in slippery conditions came about from the Goodyear Tire Company by 1908.
Early tires and wheels were made of materials which could not sufficiently contain air pressure. This, combined with inefficient mounting techniques and high tire pressures, resulted in a requirement that all tires use a rubber inner-tube, between wheel and tire, to hold the air.
The pneumatic tire made a phenomenal success of the bicycle and therefore automobile adherents expected this same principle to solve their similar but more intricate problems. Automobile tire manufacturers of the various countries logically turned their attention to the development of the types of bicycle tires in use and in consequence the single tube automobile tire appeared in America, the Dunlop Wired-on type in England, and the Clincher in France and Germany. The Single Tube, however, because of its general all-around impracticability for automobile purposes soon gave way to the others, i. e., the Clincher (developed from its prototype the Single Clincher bicycle tire) and Straight Side (developed from the Dunlop Wired-on) and these two types have predominated.
The first American made pneumatic tires for automobile use were by Winton Co., of Cleveland, Ohio and was manufactured in the middle of 1896. They were single tube type; size 34 x 4 being used for front wheels and 36 x 4 for the rear designed. Mr. Alexander Winton knew the merits of the pneumatic tire, as used on bicycles, for light automobiles. He decided when completing one of his first experimental machines, that it should be equipped with specially built tires of this type in place of the steel or solid rubber variety which were generally used by automobile experimenters.
To secure tires such as he had in mind was, however, not easy since the largest pneumatic then made was the 1.5” bicycle tire. Nevertheless Mr. Winton wanted something special and presented his proposition to Mr. A. J. Wills of The B. F. Goodrich Co., who in turn conveyed it to Mr. B. G. Work, then superintendent of our factory.
Mr. Work, it appears was skeptical of the "horse less carriage" ever becoming a commercial success but after considering the matter decided that if the Winton Co. would pay for the molds we would go ahead and see what we could do.
Mr. Winton promptly accepted the terms and placed the order and delivering the tires in October. It is said crowds in Cleveland gathered to see the vehicle fitted with tires were happy and amazed to see the enormous tires. These "burlesque" bicycle tires as they were termed, were, however, the beginning of the tremendous automobile tire industry of this continent.
Goodrich was manufacturing Clincher bicycle tires for several years, when they entered the automobile tire field they constructed tires of nineteen plies
of light fabric and, 5 developed for automobile use. The first two cross section diameters, i.e., 2.5 and 3 inches, in wheel sizes ranging from 28 to 36 inches were manufactured for sale in 1899, In 1903, they began manufacturing tires of two weights, which were termed "Light" and "Heavy Profile," the latter being made with more plies than the former and intended for use on the rear wheels only. Later in 1903, tires in larger cross sections began to appear including sizes up to 4.5 inches, although even yet very few were manufactured, the output in volume being of minor importance.
In 1904, however, the business began to assume larger proportions and began to appear in the 5" cross section. In 1906 and 1907 commenced to manufacture two styles of tread, the smooth and flat, and was the Regular Clincher (Soft Bead).
Beginning with 1907, the Q. D. Clincher (Stiff Bead) tire was brought out and their line then comprised the Regular Clincher and the Q. D. Clincher in both the round and flat contour "Bailey" and Smooth treads, which line, up to 1909, remained unchanged. Beginning with 1910, they discontinued the flat tread confining the efforts to the round contour tread which they continued to make in both Regular and Q. D. Clincher types in "Bailey" and Smooth patterns. This output for the first time, also included the Q. D. Straight Bead tire in addition to those supplied in 1909. From the advent of our "Safety" in 1912 no further radical change was made until the latter part of 1915, at which time announced their "Black Tread Rubber" to the public.
While prior to 1915 tread stock other than white or grey was not considered seriously by leading tire companies.
In 1918, Firestone Tire and Rubber Company of Canada was incorporated in Hamilton, Ontario and in 1922, the first Canadian-made tire rolled off the line on September 15. During the 1920s, Firestone produced the Oldfield tire, named for racing driver Barney Oldfield.
In 1926, the company opened one of the world's biggest rubber plantations in Liberia. West Africa, spanning more than 1 million acres. 1926 was also the year that the company opened its first Firestone Complete Auto Care store offering automotive maintenance and repair.
In 1927, Henry Ford and tire expert Harvey Firestone took a trip to Los Angeles to select locations for their new factories. Friends say Ford wanted to be near the ocean and picked Long Beach and suggested Firestone go to South Gate, California. The tiny community southeast of Downtown was mostly agriculture at the time and Firestone found 40 acres of beanfield to house his new manufacturing plant. A year after the plant opened in1928 it doubled in size.
At the beginning of auto mobile tire history all tires were made with smooth treads. However, it soon became a general belief that the smooth tread did not offer sufficient tractive qualities and was, therefore, adaptable only to the front wheels which merely roll, and consequently tire manufacturers began experimenting with traction designs. At first these "traction treads" were made solely with the idea of increasing the grip of the wheel on the road and so makers molded transverse grooves at about two-inch intervals around the circumference of the tread, which design relied on its flatness and square edges to prevent side slipping. This, on account of its flat surface, was not entirely successful because of its tendency to separate from the carcass.
Next came the corrugated tread which was composed of ridges running circumferentially around the crown of a rounded tread. Although this was some improvement over the flat tread idea in as much as it eliminated tread separation and was a more effective preventative against side slipping, it did not give as much traction as desired. And it was only natural then for tire designers to turn their attention toward a pattern which would embody the good features of both the "traction" and the "ribbed" with none of their disadvantages. The result was the well-known British Dunlop Traction Tread a series of "V" shaped grooves molded at short intervals around the circumference of the tire. This type never gained a foothold in the United States, because it was introduced about the time the automobile was coming into its own and the increasing speed of the newer machines demanded a still stronger tire and better all-around non-skid.
Increased speed of vehicles became an added danger making it an additional dimension to other types of non-skid problems. One of the most successful among these was the "Bailey," invented by the complexion brush manufacturer of that name, which tread consisted of staggered rows of rubber studs or buttons molded into tread stocks making a design similar in appearance to the surface of the massage brush. This was indeed a radical departure from the early designs, but it operated so well that it was soon used by nearly all tire makers, who paid a liberal royalty to Mr. Bailey.
Partly to avoid paying Bailey's royalty and partly because they recognized the advertising value of individual tread designs, automobile tire manufacturers soon began to bring out designs of their own. From the beginning, essentials were overlooked and all energy was directed toward producing treads that were distinctive and which in consequence could be featured in advertising.
It seems that caution was thrown to the winds; treads were designed that were suicidal to tire life because of the strain upon the fabric or because the twisting of the tread itself developed a tendency to pull it away from the carcass of the tire. Probably the worst offenders against scientific tire design were those whose treads were composed of knobs, studs, or cups so large that under the weight of the car they were forced back into the fabric of the tire, straining it so severely with each revolution of the wheel that after a limited amount of service it gave way entirely.
While this apparently misdirected scramble for individuality was going on, "Bailey" though constantly looking for a better design—one along lines that conformed to the natural workings of the tire itself. Instead of rushing blindly into a tread, Goodrich profited by the experience of others, recognizing and utilizing the merits of both the "traction" and "corrugated" treads and avoiding the pitfall of faulty or careless design.
The Safety Tread
Goodrich after careful study of the development of non-skids and the correct application of all the good features brought out Safety Tread Tire. The "Safety" as a result embodies not only all the non-skid features of the early types, but what is more important, its design is such that no more strain is carried to the fabric body than is the case with a smooth tread tire.
The design of our Safety Tread, consisting of a series of rubber bars with cross ties:
1—Continuous traction and protection from forward and backward slip.
2—The same protection from side slip that was provided in the early days by the square outside edge of the flat tread tire and the ribs of the corrugated tread.
3—Freedom from strain to the fabric walls of the tire.
That the Safety Tread is effective in carrying out its particular purpose has been positively proven by the service it has given. Motorists everywhere have testified as to its superiority over other Non-skid designs. It reduced forward and backward slipping, and under ordinary circumstances prevented sidewise skidding as well.
In 1904, the Continental AG Company in Germany produced the world's first automobile tire with a patterned tread. Frank Seiberling of the Goodyear Tire & Rubber Company invented grooved tyres with improved road traction in 1908. By the early 1920s there were more than 400 companies manufacturing tires in the USA.
The George Grow Tire Company that produced tires from 1919 to 1925 at Canton Junction, Boston, was typical of the many manufacturers that existed, producing at its peak over 500 per day.
It became the trademark tread for the company's popular "Ward Tire". Sipes are the small slots that are cut into the surface of a tire tread to increase traction on wet, snowy or muddy road surfaces. On November 2 1920 John F Sipe filed a US patent application for “Elastic Tire and Method of Making Same”. It related to a solid rubber tire.
It wasn’t until the 1950s, when improved tread compounds were developed, that the sipe process was applied to tires on a large scale. The US National Safety Council reported in 1978 that siping improved stopping distances by 22 percent on glare (black) ice.
Invention and History of the Silvertown Cord.
Since the days when the first pneumatic tire was first recognized as the boon of the automobile industry, many ideas for improving it have been evolved and patented. Some of these were freakish and entirely impractical, while others were of sufficient merit to attract general attention. However, being no improvement on the then existing types in the manner of their application to the wheel, their wearing and shock absorbing qualities, these numerous patents have been with few exceptions, soon discarded by the leading manufacturers as useless.
One exception standing out above all others as not only embodying all the fundamental principles of correct tire construction but as a decided improvement on all types, was the idea of the cabled cord tire invented and perfected in Silvertown, England, in 1904 by C. H. Gray and Thomas Sloper.
Although tire manufacturers soon after the establishment of the first automobile factories had fairly perfected the regular fabric construction, it was early recognized that the "tire ideal" would be one of one ply of rubber and fabric, or any other material that could "harness air" and at the same time be tough enough to withstand the wear and tear of road service. However, it was found impossible to compound rubber or weave fabric strong enough to be used in the construction of a single ply tire, and therefore, the next step was to attempt the development of a tire of two plies, if possible.
Mr. Thomas Sloper, an Englishman, had taken occasion to visit a bicycle show in London during 1888, where he became interested in a pneumatic bicycle tire, and later purchased a bicycle for no other purpose than to make a study of the structure of this tire. After examining the carcass and finding that it was made of woven fabric, the thought occurred to him that it might be possible to build a better carcass by the use of fine cord as the strengthening agent. Subsequently, he experimented with a thread construction, taking out a patent in 1889 and presenting the idea to leading tire manufacturers. But he was ridiculed by all of them.
With this same idea in mind, Mr. John F. Palmer of Chicago, later began experimenting on a tire of similar construction, patenting the same in America about 1892; as he had rightly determined that although the fabric tire answered its purpose fairly well, it had its shortcomings. His conclusions were that as fabric tires were built of several plies which must be so vulcanized together that they operated as a unit, and in as much as the warp and filler of square woven duck are normally disposed at right angles to each other, it would be impossible to manufacture a tire of this fabric, even when cut on the bias with anywhere near a uniform tension of the threads, without which a tire of absolutely consistent performance could not be secured.
Furthermore, by reason of the warp and filler threads being interwoven, and operating under high tension, he concluded there would be resistance to bending or distortion with the added disadvantage that such bending would set up movements in the interwoven warp and filler of the square woven fabric resulting in heat and wear.
Mr. Palmer's conclusions were entirely accurate and even today with fabric tire construction "balanced" and perfected, it is impossible to go beyond the very definitely described limitations of woven duck in attempting to build a multiple ply tire of both maximum strength and maximum resiliency. The difficulty of uniform tension of warp and weave in the body of such a tire is unsurmountable.
Then again, tire fabric is not woven in sufficient widths to permit its being bias cut, as it must be, in strips long enough to form one continuous length and in consequence there must be one or more splices in each carcass. Wherever such a joint occurs resistance to flexing of the body fabric is doubled and when this is multiplied by the number of plies made necessary to give strength in a fabric tire, the wonder is that they perform as well as they do.
C. H. Gray of Silvertown, England, who had by the way, purchased the English rights to Mr. Palmer's tire and who also had experimented with the cord construction for automobile tire purposes, in partnership with Thomas Sloper of the same place finally came out with a cord automobile tire in 1904. Six years later, the American rights to their patents were purchased out right by the Diamond Rubber Company, and were inherited by Goodrich at the time of the Diamond-Goodrich consolidation in 1912. They developed and perfected this cord principle to a point the Goodrich Silvertown is the strongest and best tire possible to build. In speed, endurance and resilience it has no rival.
To sum up John Fullerton Palmer invented the cord tire in 1889. This "weftless" or "all-warp" cords prolonged the casing or carcass life by eliminating the abrasion of cord rubbing on cord, as it was the case with the previous cross-woven cotton tire reinforcement. The cord tire didn't actually become a commercial reality for more than a decade, when it was introduced in England by the inventor's own Palmer Cord Tyre Co. and in the U.S. by B.F. Goodrich Rubber Co.
Bias Ply Construction
By the 1910s, tire engineering and manufacturing had evolved to use sheets of cotton cord material, cut at an angle (“on the bias”), layered, and molded into sheet rubber. So was born the “bias ply tire,” which remained the industry standard, at least in the U.S., until the 1960s.
In early part of 20th century by 1918 tire industry had undergone a dramatic change; automobile tires were then accounting for about 50 percent of rubber sales. In 1901, when seven thousand new cars were sold, the rubber industry produced 96,000 automobile tires, including replacement tires. ln 1918, with a million new cars on the market, total tire production reached 24.5 million.
Such a huge increase in production would not have been possible without improvements in technology. Before 1909, when W.C. State of the Goodyear Tire Sr Rubber Company patented the tire building machine.
Earlier workers made tires by manually stretching, cementing and stitching each ply around an iron core. One worker could make six to eight tires in a day. With tire-building machine, a worker’s productivity increased to twenty to forty tires in a day, depending on the type of tire.
The principal innovative feature of the machine was a set of rollers on a central turret that carried plies, beads, and tread. As the worker pulled the materials over the core, the machine‘s electric motor held the proper tension so the worker could finish cementing and stitching. Although manual dexterity and skill remained important. the introduction of State's machine marked the beginning of mass production in the rubber industry.
Germany's Continental A.G. introduced a pneumatic truck tire in 1911 and such tires were fitted on a limited number of commercial trucks the following year. However, most truck owners continued using solid rubber tires until the early 1920s, when manufacturers undertook extensive promotional campaigns demonstrating the superiority of pneumatics.
Radial-ply tire patented, 1913, by Christian Hamilton Gray and Thomas Sloper of Silvertown, Essex, England. However, their company never commercialized the invention.
In 1915 the Palmer Tire Company in Detroit produced the first cord “cross-ply” tire using a "sandwiching" construction technique that significantly reduced tire wear. Cross-ply tires are also called as we mentioned bias-ply tires. The fabric was no longer woven; strands of cotton cord were used and laid parallel to each other and pressed into sheet rubber. The carcass of the tire being produced by laying sheets of cord material cut on the bias/angle and laid across each other. A tire’s framework is called the “carcass” and consists of the entire inner layer of cord fabric. It acts to support air pressure, vertical load and absorb shocks and is composed of multiple layers called plies or belts.
Banbury mixer invented, 1916, by F.H. Banbury to speed the process of mixing chemicals and uncured rubber.
First cross-country truck line established in the U.S. by Goodyear, 1917, to demonstrate the superiority of pneumatics over solid truck tires.
Firestone carried on a five-year advertising campaign to sell the concept commercially.
White sidewalls introduced, 1918, by the then newly founded Vogue Tyre & Rubber Co, of Chicago, which contracted with Falls Rubber Co. in Cuyahoga Falls, Ohio, to make them. First customers were chauffeurs and owners of luxury cars of that era.
By 1919 the British Palmer Tire Company had seven offices in Great Britain, one in Paris and another Amsterdam and was advertising its new cross-ply tire.
Low-pressure (balloon) tires introduced, 1923, by Group Michelin in Europe and Firestone Tire & Rubber Co. in the U.S. Characterized by bulging sidewalls and nearly twice the tread width, they permitted inflation pressures as low as 28 psi-about half that of previous pneumatic tires. Use of such tires, however, was not widespread in the U.S. until the 1930s when the concept was popularized by General Tire Co.
Antioxidants introduced, 1924, to reduce rubber degradation resulting from exposure to oxygen, ozone and ultraviolet radiation from the sun. Generally credited with independently developing the first commercially feasible antioxidants were Herbert A. Winkelmann and Harold Gray of B.F. Goodrich Rubber Co. and Sidney M. Cadwell of U.S. Rubber Co.
In the 1930s rayon replace the cotton in cord belts. In 1943 nylon cord was introduced; steel-cord in 1959 and fiberglass cord in 1963.
From the late 1940s until the early 1960s most car tires were classified 4-ply; 2 layers, or 2 pairs of plies.
In 1965-66 the American Armstrong Tire and Rubber Company introduced the first belted bias tire. Layers of fiberglass were laid under the tread of a conventional bias-ply tire.
In 1967, also by adding a fiberglass belt to a bias-ply tire, Goodyear introduced a commercially successful “bias-belt” product called the Custom Superwide Polyglas. Belted bias tires are produced by adding two or more belts that are positioned between the bias plies and the tread rubber and run lengthwise around the circumference of the tire.
Over the years the degree of bias used by differing manufacturers has varied from about 30 to 55 degrees relative to the rim of the tire’s rim.
In America on 21May 1915 Arthur Savage of the San Diego Savage Tire Comp any filed a patent for designs of a radial tire. He was granted US patent on 7 November 1916; which expired in 1949.
Savage and Gray & Sloper did not though produce a radial tire based on their patents. The first all-steel reinforced radial tire was produced and patented by Pierre Marcel Bourdon of Michelin in 1946.
Michelin had bought the bankrupt Citroën automobile company in 1934, so it was able to fit this new technology immediately. In the new radial tire the reinforcing cords were at 90 degrees (radial) to the wheel. A steel wire restraining belt, located over the radial cords and under the tread, running around the circumference of the tire.
Because of its superiority in handling and fuel economy, use of this technology quickly spread throughout Europe and Asia but not in under developed and developing countries like India as roads were not suitable for radial tires.
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%.
In addition to Michelin the early major radial tire producers included Bridgestone (Japan), Pirelli (Italy) and Continental (Germany). Due to costly production implications, the introduction of the radial tire ultimately resulted in the worldwide closure of more than 50 tire plants.
In 1965 the B F Goodrich Company, with the introduced of the “Silvertown Radial 900”, became the first American tire manufacturer to produce radial tires.
The Balloon Tire
In America on 3 October 1894 Edward E Pennington submitted a motor cycle patent application No. 524, 833 which included reference to the use and advantages of “a pneumatic tire of an extra-large diameter”. “The larger the diameter of the tire the less the pressure per square inch”.
In 1896, he produced a two wheeled gasoline powered “Motor Cycle” machine which was equipped with extra-large diameter “balloon” tires.
On 29 December,1896 a “motor-vehicle specification forming part of letter patent No. 574,262” was granted to Edward J Pennington. Prior to the balloon tire early pneumatic tires had to be pressurised to 70 psi (4.8 bar) or greater in order to prevent them leaving the rim at speed. The pressure used on Goodrich’s 30 x 3 ½ inch tires was typical; 60 psi for a 400 lb load or 70 psi for a 500 lb load.
When commercial production of car balloon tires started in the 1920 they were typically pressurised to 35 psi (2.4 bar) and 4.5 inches (114 mm) wide. Michelin and Firestone were the first balloon tire manufacturers. In the early 1920s Michelin developed a 115mm (4.5 inch) wide balloon tire called “Comfort”, producing over one million by October 1924. The Firestone Tire and Rubber Company started production of balloon “gum-dipped cord” tires in April 1923. By the end of 1924 over 60% of the 111 different car models available in the USA were supplied with balloon tires. By 1926 4.40 inch (112mm) wide balloon tires were supplied as standard fit on the Model T Ford (and as a $25 option in 1925). In the 1940s a more comfortable “super balloon” tyre was produced which had a larger volume of air.
Tires width’s increased significantly over the years. By 2011 the Rolls Royce Phantom L model was, for example, fitted with 265mm (10.43 inch) wide tires.
Use of Carbon Black
Carbon Black became one of the ingredients of rubber compounds. In what way carbon black reinforces elastomers is one of the most interesting problems of modern technology and still a subject of much speculation. The effect was discovered by S. C. Mote of the India-Rubber, Gutta-Percha and Telegraph Works Co. of Silvertown, as a result of an effort to improve the properties of rubber even more than was possible by zinc oxide. The Goodrich Company purchased certain manufacturing rights from the Silvertown company in 1912, and by 1915, the inclusion of carbon black in rubber compounds of high quality had become general. The most important effect observed upon introduction of carbon black into rubber was the vast improvement in abrasion resistance.
As long as natural rubber was the unique elastomer in general use, other effects of carbon black, although by no means insignificant, were not of the same great importance, with the possible exception of tear resistance. With the outbreak of war in 1939 and the consequent shortage of natural rubber in the industrial West, the introduction of the copolymer of butadiene and styrene, then known as Buna or GR-S, as an almost total replacement for natural rubber, would not have been possible without carbon black. It may be stated, with little likelihood of contradiction, that no other product exists which contributes as much strength and abrasion resistance to non-crystallizing rubbers, while maintaining to a large extent their desirable elastic properties, as does carbon black.
Straight-side wire-bead tire
In 1904. The straight-side wire-bead tire was developed simultaneously by Goodyear and the former Firestone Tire & Rubber Co., which had been working independently to replace the heavily patented clincher tire. Within four years, the straight-side tire replaced the clincher as the industry standard in the U.S.
Organic accelerators introduced, 1906. Use of organic accelerators to shorten rubber's curing time and thereby speed up tire production was pioneered by George Oenslager of the Diamond Rubber Co. He also introduced the use of carbon blacks in treads in 1911.
Dual wheels and tires, 1908. Group Michelin introduced the concept of dual wheels and tires, increasing the payload on trucks and buses used in France.
Spares & Repairs
In 1903 the addition of cord to the tyre made them more robust but horses were still very common and horseshoe nails on the roads remained a major cause of punctures. In 1904 Walter and Tom Davies (Welsh) patented a spare wheel that could be attached to a wheel with a punctured tyre by adjustable clamps. The “Stepney Spare Wheel” was a spokeless wheel rim onto which a tire of slightly larger than usual diameter was mounted.
In 1906, they formed the Stepney Spare Motor Wheel Company and within three years it had been fitted to more than 75,000 cars. By 1910 the company had agencies in Europe and North America; including the Stepney Motor Wheel of Canada Limited. The American Thomas B. Jeffery Company was the first car manufacturer to offer a spare tire.
In 1909 the company was the second largest car manufacturer in the world. In 1909 their five passenger Rambler 44 model sold for $2,250 and for an extra $74 an extra wheel and inflated tire was provided.
Mountable rims were introduced in 1904; allowing drivers, because the early tires where much softer than modern ones, to remove, replace/ repair their own flat tires. In Germany in 1908 Continental AG invented a detachable rim for sedans which made changing a tire much simpler.
In about 1910 the Danish postal service noted that in Copenhagen their cars could expect a puncture every 491 km (307 miles) and possibly every 200 km (125 miles) in the countryside. A “Continental tire” is the name given to an upright, externally mounted spare tire located behind a car’s boot (trunk) compartment. It derives its name from the 1939 Lincoln Continental model it was first fitted to.
In 1941 (WW2) and in 1951 (Korean War) spare tires were banned on new cars the US. In the 1950s spare wheels started to be carried in a recess in the floor of the luggage compartment or 'boot'.
In Europe “Boot” derives from the use made of the sturdy chest that was used to carry valuable goods which also served as a foot/boot rest for the driver of a horse drawn coach.
In America, the same space was used to carry a trunk, not a chest. The Dunlop Company introduced safety tyres in 1972 which sealed themselves after a puncture. The compact spare tire was designed by P. Fletcher for the Volkswagen Automobile Company in the 1980′s.
Aircraft tires, 1909. The first pneumatic airplane tires were introduced by Goodyear and United States Rubber Co.
Winter-tread tire, 1909. Continental A.G. of Germany introduced a tire sporting an aggressive tread pattern designed for use in winter snow and mud.
Interesting Facts & Figures
About 300,000 tires (and 4,200 cars) were produced in the USA in 1900. Car manufacturers ceased using solid tires in 1929. By 1998 over 250 million tires were produced annually in the USA and over 416 million worldwide. The size of a tire was originally established by measuring outer diameter. This was later changed to measuring the inner rim diameter.
World demand to rise 4.1% annually through 2019
World demand for tires is projected to rise 4.1 percent per year to 3.0 billion units in 2019. In value terms, sales of tires are forecast to advance 7.0 percent per annum to $258 billion.