Monday, June 30, 2008


No single person or nation can be credited with the invention of the typewriter. As with the light bulb, automobile, telephone, and telegraph, a number of people contributed insights and inventions that eventually resulted in commercially successful instruments. In fact, historians have estimated that some form of typewriter was invented 52 times as tinkerers tried to come up with a workable design.
In 1714, Henry Mill obtained a patent in Britain for a machine that, from the patent, appears to have been similar to a typewriter, but nothing further is known. Other early developers of typewriting machines include Pellegrino Turri, who also invented carbon paper. Many of these early machines, including Turri's, were developed to enable the blind to write.
In 1829, William Austin Burt patented a machine called the "Typographer." Like many other early machines, it is sometimes listed as the "first typewriter"; the Science Museum (London) describes it merely as "the first writing mechanism whose invention was documented," but even that claim may be excessive, since Turri's machine is well known. Even in the hands of its inventor, it was slower than handwriting. Burt and his promoter John D. Sheldon never found a buyer for the patent, and it was never commercially produced. Because it used a dial to select each character rather than keys, it was called an "index typewriter" rather than a "keyboard typewriter," if it is to be considered a typewriter at all.
By the mid-1800s, the increasing pace of business communication was creating a need for mechanization of the writing process. Stenographers and telegraphers could take down information at rates up to 130 words per minute, but a writer with a pen was limited to about 30 words per minute (the 1853 speed record). From 1829 to 1870, many printing or typing machines were patented by inventors in Europe and America, but none went into commercial production.
Charles Thurber developed multiple patents; his first, in 1843, was developed as an aid to the blind. See Charles Thurber's 1845 Chirographer, as an example. In 1855, the Italian Giuseppe Ravizza created a prototype typewriter called "Cembalo scrivano o macchina da scrivere a tasti." It was an advanced machine that let the user see the writing as it was typed. In 1861, Father Francisco João de Azevedo, a Brazilian priest, made his own typewriter with basic materials and tools, such as wood and knives. D. Pedro I, the Brazilian emperor, in that same year, presented a gold medal to Father Azevedo for this invention. Many Brazilian people as well as the Brazilian federal government recognize Fr. Azevedo as the real inventor of the typewriter, a claim that has been the subject of some controversy. Between 1864 and 1867 Peter Mitterhofer, a carpenter from South Tyrol (then Austria) developed several models of a typewriter and a fully functioning prototype in 1867.

In 1865, Rev. Rasmus Malling-Hansen of Denmark invented the Hansen Writing Ball, which went into commercial production in 1870 and was the first commercially sold typewriter. It was a success in Europe and was reported as being used in offices in London as late as 1909.In addition, Malling-Hansen used a solenoid escapement to return the carriage on some of his models and was a responsible candidate for the first "electric" typewriter. From the book Hvem er Skrivekuglens Opfinder?, written by Malling-Hansen's daughter, Johanne Agerskov, we know that, in 1865, Malling-Hansen made a porcelain model of the keyboard of his writing ball and experimented with different placements of the letters to achieve the fastest writing speed. Malling-Hansen placed the letters on short pistons that went directly through the ball and down to the paper. This, together with placement of the letters so that the fastest writing fingers struck the most frequently used letters, made the Hansen Writing Ball the first typewriter to produce text substantially faster than a person could write by hand.
Malling-Hansen developed his typewriter further through the 1870s and 1880s and made many improvements, but the writing head remained the same. On the first model of the writing ball from 1870, the paper was attached to a cylinder inside a wooden box. In 1874, the cylinder was replaced by a carriage, moving beneath the writing head. Then, in 1875, the well-known tall model was patented and it was the first of the writing balls that worked without electricity. Malling-Hansen attended the world exhibitions in Vienna in 1873 and Paris in 1878. At both exhibitions, he received the first-prize medals for his invention.

The first typewriter to be commercially successful was invented in 1867 by Christopher Sholes,[1] Carlos Glidden and Samuel W. Soule in Milwaukee, Wisconsin. Sholes soon disowned the machine and refused to use or even to recommend it. The patent (US 79,265) was sold for $12,000 to Densmore and Yost, who made an agreement with E. Remington and Sons (then famous as a manufacturer of sewing machines) to commercialize what was known as the Sholes and Glidden Type-Writer. Remington started production of its first typewriter on March 1, 1873, in Ilion, New York. Another early typewriter manufacturer was Underwood.

The ability to view what is typed, as it is typed, is taken for granted today. In most early keyboard typewriters, however, the typebars struck upward against the bottom of the platen. Thus, what was typed was not visible until the typing of subsequent lines caused it to scroll into view. The difficulty with any other arrangement was ensuring that the typebars fell back into place reliably when the key was released. This was eventually achieved with various ingenious mechanical designs and so-called "visible typewriters", such as the Oliver typewriter, were introduced in 1895. Surprisingly, the older style continued in production to as late as 1915.

By about 1910, the "manual" or "mechanical" typewriter had reached a somewhat standardized design. There were minor variations from one manufacturer to another, but most typewriters followed the concept that each key was attached to a typebar that had the corresponding letter molded, in reverse, into its striking head. To have letters typed in exact location, the typebar was guided all its way till the ribbon by segment. When a key was struck briskly and firmly, the typebar hit a ribbon (usually made of inked fabric) stretched in front of a cylindrical platen that moved back and forth. The paper was rolled around by the typewriter's platen, which was then rotated by the "carriage return" lever (at the far left) into position for each new line of text.
A significant innovation was the Shift key. This key physically "shifted" the basket of typebars, so that a different portion of the bar would come in contact with the ribbon/platen. The result is that each typebar could type two different characters, cutting the number of keys and typebars in half (and simplifying the internal mechanisms considerably). The obvious use for this was to allow letter keys to type both upper and lower case, but normally the number keys were also duplexed, allowing access to special symbols such as percent (%) and ampersand (&). With the Shift key, manufacturing costs (and therefore purchase price) were greatly reduced, and typist operation was simplified; both factors contributed greatly to mass adoption of the technology.
Because the Shift key required more force to push (its mechanism was moving a much larger mass than other keys), and was operated by the "pinky" finger (normally the weakest finger on the hand), it was difficult to hold the Shift down for more than two or three consecutive strokes. The "Shift Lock" key (the precursor to the modern Caps Lock) allowed the shift operation to be maintained indefinitely. Unlike the today's Caps Lock, however, the Shift Lock was a two-key operation: Shift would be held down, and the Shift Lock (normally directly above) would be pressed simultaneously, triggering a simple lock mechanism. To unlock, Shift was tapped again, releasing both keys and unshifting the basket.
Some ribbons were inked in black and red stripes, each being half the width and the entire length of the ribbon. A lever on most machines allowed switching between colors, which was useful for bookkeeping entries where negative amounts had to be in red.
In the 1940s, a silent typewriter was marketed, but it failed, leading some observers to the conclusion that the clickety-clack of the typical typewriter was a consumer preference.

Electric Designs
Although electric typewriters would not achieve widespread popularity until nearly a century later, the basic groundwork for the electric typewriter was laid by the Universal Stock Ticker, invented by Thomas Edison in 1870. This device remotely printed letters and numbers on a stream of paper tape from input generated by a specially designed typewriter at the other end of a telegraph line.
The first electric typewriter was produced by the Blickensderfer Manufacturing Company, of Stamford, Connecticut, in 1902. While never marketed commercially, this was the first known typewriter to use a typewheel rather than individual typebars, although the element was cylindrical rather than ball-shaped. The next step in the development of the electric typewriter came in 1909, when Charles and Howard Krum file a patent for the first practical teletype machine. The Krums' machine also used a typewheel rather than individual typebars. While innovative, neither of these machines reached the business or personal consumer.
Electrical typewriter designs removed the direct mechanical connection between the keys and the element that struck the paper. Not to be confused with later electronic typewriters, electric typewriters contained only a single electrical component: the motor. Where the keystroke had previously moved a typebar directly, now it engaged mechanical linkages that directed mechanical power from the motor into the typebar. This was also true of the forthcoming IBM Selectric.
IBM and Remington Rand electric typewriters were the leading models until IBM introduced the IBM Selectric typewriter, which replaced the typebars with a spherical element (or typeball) slightly larger than a golf ball, with the reverse-image letters molded around its surface. The Selectric used a system of latches, metal tapes, and pulleys driven by an electric motor to rotate the ball into the correct position and then strike it against the ribbon and platen. The typeball moved laterally in front of the paper instead of the former platen-carrying carriage moving the paper across a stationary print position.

The typeball design had many advantages, especially the elimination of "jams" (when more than one key was struck at once and the levers became entangled) and in the ability to change the typeball, allowing multiple fonts to be used in a single document. Selectric mechanisms were widely incorporated into computer terminals in the 1960s, because the typing mechanism (a) was reasonably fast and jam-free, (b) could produce high quality output compared to competitors such as Teletype machines, (c) could be initiated by a short, low-force mechanical action, (d) did not require the movement of a heavy "type basket" to shift between lower- and upper-case, and (e) did not require the platen roller assembly to move from side to side (a problem with continuous-feed paper). The IBM 2741 terminal was a popular example of a Selectric-based computer terminal, and similar mechanisms were employed as the console devices for many IBM System/360 computers. These mechanisms used "ruggedized" designs compared to those in standard commercial typewriters.
IBM also gained an advantage by marketing more heavily to schools than did Remington, with the idea that students who learned to type on an IBM Electric would later choose IBM typewriters over the competition in the workplace as businesses replaced their old manual models.
Later models of IBM Executives and Selectrics replaced inked fabric ribbons with "carbon film" ribbons that had a dry black or colored powder on a clear plastic tape. These could be used only once, but later models used a cartridge that was simple to replace. A side effect of this technology was that the text typed on the machine could be easily read from the used ribbon, raising issues where the machines were used for preparing classified documents (ribbons had to be accounted for to ensure that typists didn't carry them from the facility). In fact, a document reconstructed from a used carbon ribbon was the key to solving a crime in an episode of Columbo.

A variation known as "Correcting Selectrics" introduced a correction feature, where a sticky tape in front of the print ribbon could remove the black-powdered image of a typed character, eliminating the need for white dab-on paint or hard erasers that could tear the paper. These machines also introduced selectable "pitch" so that the typewriter could be switched between pica (10 characters per inch) and elite (12 per inch), even within one document. Even so, all Selectrics were monospaced—each character and letterspace was allotted the same width on the page, from a capital "W" to a period. Although IBM had produced a successful typebar-based machine with three levels of proportional spacing, called the IBM Executive, no proportionally spaced Selectric office typewriter was ever introduced. There were, however, two other machines with fully proportional spacing: the expensive Selectric Composer, which was capable of right-margin justification and was considered a typesetting machine rather than a typewriter; and the more reasonably priced IBM Electronic Typewriter 50, which was capable of proportional spacing but not right-justifying. By 1970, as offset printing began to replace letterpress printing, the Composer would be adapted as the output unit for a typesetting system. The system included a computer-driven input station to capture the key strokes on magnetic tape and insert the operator's format commands, and a Composer unit to read the tape and produce the formatted text for photo reproduction.
The final major development of the typewriter was the "electronic" typewriter. Most of these replaced the typeball with a daisy wheel mechanism (a disk with the letters molded on the outside edge of the "petals"). A plastic daisy-wheel was much simpler and cheaper than the typeball but also wore out more easily. Some electronic typewriters were in essence dedicated word processors with internal memory and cartridge or diskette external memory-storage devices. Unlike the Selectrics and earlier models, these really were "electronic" and relied on integrated circuits and multiple electromechanical components.
From Wikipedia, the free encyclopedia

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