sâmbătă, 23 februarie 2008

Roller skates inventors


The first recorded use of roller skates was in a London stage performance in 1743. The inventor of this skate is lost to history. The first recorded skate inventor was Jean-Joseph Merlin, who demonstrated a primitive inline skate with metal wheels in 1760. The first patented roller skate design was patented in France by M. Petitbled, in 1819. These early skates were similar to today's inline skates, but they were not very maneuverable; it was very difficult with these skates to do anything but move in a straight line and perhaps make wide sweeping turns. During the rest of the 19th century, inventors continued to work on improving skate design.
An advert for an early 20th century model which fit over regular shoes.

The four-wheeled turning roller skate, or quad skate, with four wheels set in two side-by-side pairs, was first designed in 1863 in New York City by James Leonard Plimpton in an attempt to improve upon previous designs, The skate contained a pivoting action using a rubber cushion that allowed the skater to skate a curve just by leaning to one side. It was a huge success, so much that the first public skating rink was opened in 1866 in Newport, Rhode Island with the support of Plimpton. The design of the quad skate allowed easier turns and maneuverability, and the quad skate came to dominate the industry for more than a century.

Arguably, the most important advance in the realistic use of roller skates as a pleasurable pastime took place in Birmingham, England in 1876 when William Bown patented a design for the wheels of roller skates. Bown's design embodied his effort to keep the two bearing surfaces of an axle, fixed and moving, apart. Bown worked closely with Joseph Henry Hughes, who drew up the patent for a ball or roller bearing race for bicycle and carriage wheels in 1877. Hughes' patent included all the elements of an adjustable system. These two men are thus responsible for modern day roller skate and skateboard wheels, as well as the ball bearing race inclusion in velocipedes -- later to become motorbikes and automobiles.

Another improvement came in 1876, when the toe stop was first patented. This provided skaters with the ability to stop promptly upon tipping the skate onto the toe. Toe stops are still used today on most quad skates and on some types of inline skates.
The classic (pre-inline) "quad" roller skate design of four wheels in a rectangular pattern.
The classic (pre-inline) "quad" roller skate design of four wheels in a rectangular pattern.

Roller skates were being mass produced in America as early as the 1880s, the sport's first of several boom periods. Micajah C. Henley of Richmond, Indiana produced thousands of skates every week during peak sales. Henley skates were the first skate with adjustable tension via a screw, the ancestor of the kingbolt mechanism on modern quad skates.

In 1884 Levant M. Richardson received a patent for the use of steel ball bearings in skate wheels to reduce friction, allowing skaters to increase speed with minimum effort. In 1898, Richardson started the Richardson Ball Bearing and Skate Company, which provided skates to most professional skate racers of the time, including Harley Davidson (no relation to the Harley-Davidson motorcycle brand). (Turner and Zaidman, 1997).

The design of the quad skate has remained essentially unchanged since then, and remained as the dominant roller skate design until nearly the end of the 20th century. The quad skate has begun to make a comeback recently due to the popularity of roller derby and jam skating.

In 1979 Scott Olson and Brennan Olson of Minneapolis, Minnesota came across a pair of inline skates created in the 1960s by the Chicago Roller Skate Company and, seeing the potential for off-ice hockey training, set about redesigning the skates using modern materials and attaching ice hockey boots. A few years later Scott Olson began heavily promoting the skates and launched the company Rollerblade, Inc.. During the late 1980s and early 1990s, the Rollerblade-branded skates became so successful that they inspired many other companies to create similar inline skates, and the inline design became more popular than the traditional quads. The Rollerblade skates became synonymous in the minds of many with "inline skates" and skating, so much so that many people came to call any form of skating "Rollerblading," thus becoming a genericized trademark.

For much of the 1980s and into the 1990s, inline skate models typically sold for general public use employed a hard plastic boot, similar to ski boots. In or about 1995, "soft boot" designs were introduced to the market, primarily by the sporting goods firm K2 Inc., and promoted for use as fitness skates. Other companies quickly followed, and by the early 2000s the use of hard shell skates became primarily limited to the aggressive skating discipline.

The single-wheel "quintessence skate" [1] was made in 1988 by Miyshael F. Gailson of Caples Lake Resort, California, for the purpose of cross-country ski skating and telemark skiing training. Other skate designs have been experimented with over the years, including two wheeled (heel and toe) inline skates, but the vast majority of skates on the market today are either quad or standard inline design.

Inline skates usually have 4 or 5 wheels, arranged in a single line. Most commonly, if they have a stop, it is a heel stop. Inline skating is often done on the same surfaces as skateboarding: on the road, sidewalk, various street furnishings like fences and steps, and on special tracks and areas. Some inline skaters compete in artistic skating events, though quads are still more typical for that use. Inline skates for artistic use tend to be designed more as an analog of the ice skate or artistic quad skate design, with a toe stop and rockered wheels.

The growth of inline skating in the United States was explosive in the early 1990s, but since 1996 sales have dropped as the market became saturated, many retailers failed to offer lessons on how to use the heel brake effectively and the sport's trendy status began to fade. Among children, inline skates were supplanted in popularity by new designs of kick scooters; meanwhile for adolescents there was a resurgence in the popularity of skateboarding. Today inline skaters can be found sharing public and private skateparks with skateboarders in cities around the world.

Because inline skating is associated with a variety of potential injuries (particular wrist and other orthopedic fractures), proper safety equipment is strongly recommended, including wrist guards, knee, elbow pads, a helmet. New skaters should consider getting rollerblading lessons from certified instructors.

miercuri, 20 februarie 2008

The Invention of the Bicycle


The earliest bicycle was a wooden scooter-like contraption called a celerifere; it was invented about 1790 by Comte Mede de Sivrac of France. In 1816, Baron Karl von Drais de Sauerbrun, of Germany, invented a model with a steering bar attached to the front wheel, which he called a Draisienne. It has two wheels (of the same size), and the rider sat between the two wheels, but there were no pedals; to move, you had to propel the bicycle forward using your feet (a bit like a scooter). He exhibited his bicycle in Paris on April 6, 1818.

Kirkpatrick MacMillan (1812-1878), a blacksmith from Dumfriesshire, Scotland, invented the first bicycle with foot pedals in the 1830 to 1840's, but he never patented it and his idea did not catch on locally.

A French father-and-son team of carriage-makers, Pierre and Ernest Michaux, invented an improved bicycle in the 1860's. Many early bicycles (called velocipedes, meaning "fast foot," or, more descriptively, "bone shakers") had huge front wheels - it was thought that the bigger the wheel, the faster you could go. Early tires were wooden - metal tires were an improvement, and solid rubber tires were added later. A chain with sprockets was added to the bicycle in the 1880's; this was called the "safety bicycle." Air-filled tires were also added in the 1880's. The derailleur gear system was added in the 1970's.