Technological+Advancements+in+Mechanical+Type

=Technological Advancements in Mechanical Type=

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Introduction
Technological shortcomings in reprography prevented commonplace duplication of written materials. Previous methodologies proved disorderly and required specialized equipment and skills not yet widely distributed. The adaptation of movable type to a desktop machine requiring a modicum of skill from one operator revolutionized the production of written words.

The First Writing Machines
The first writing machines were produced in prototype form prior to 1870, but prior to the 1890s did not resemble the typewriters of our memory. By 1900, the general public began to accept a typing machine that offered the speed of a hand-written document, and could reliably do so with comfort.

Typewriters were entirely mechanical devices, swinging cast character impressions onto the page by the force of the typist's fingers. Characters were embossed onto the page using a carbon ribbon, traditionally a fabric tape. The contraptions were often held in hand-made wooden chassis, but began to be manufactured from cast metals.

Typewriter Hardware
The primary components of a typewriter are:

Keyboard
The operator interfaces with keys laid-out in a variety of patterns, eventually settling on the current QWERTY system. Each key operated one type-bar, or character onto the page. Pressing a key typed the character and advanced the platen or carriage one unit of type (escapement).

Type Element(s)
The characters are typed onto the page by embossed letters, either mounted on typebars, rollers, spheres, or daisy-wheels.

Platen
The platen is the rubber roller that holds the paper page. In earlier systems, the platen and the page would move left/right to position the current character space in front of the type elements. Rotating the platen changes the horizontal line which text is typed on to.

Carrier
In later models (approaching 1960), the platen was fixed within the body of the typewriter. To type across the page, the type element(s) would move across the platen on a carrier.

Margins and Tabulation
Typewriters' characteristic dinging bell occurs when the platen or carrier approaches the right margin. The positions of the left and right margins could be set relative to the platen, and "tab stops" could be set to rapidly escape the platen or carrier to those positions.

Optimization of Classical Typewriters


During the period between 1900 and 1950, the technology involved in typewriter mechanics stayed relatively consistent, but was continually refined. During this time, manufacturers developed speed competitions which reached current-day computerized typing speed. Mechanical typewriters were ubiquitous and universally accepted as a fact of daily business, leading to numerous cultural changes.

Modern typewriters adapted the styles of the time, and used new materials to decrease weight, increase portability, and optimize mass production.

Electric Typewriters
Around 1950, electric typewriters began invading the marketplace over mechanical typewriters. At first, employers were weary of converting as these new devices were more complex and consequently more expensive. Despite the high initial cost, the electric typewriters proved faster causing an increase in productivity and saving customers money in the long run. Electric typewriters provided increases of anywhere from 10-30% in productivity and therefore quickly became the industry standard[14].

Electric typewriters improved efficiency for a variety of reasons. The most noticeable reason for the user was the electric-motor-assist in typing. On traditional mechanical typewriters, the keys required relatively high force with large travel and would tire the typists fingers out quickly. The keys on electric typewriters would travel much less and required negligible force -- just enough to complete the circuit below the key activating a complex system of pulleys, gears, shafts, motors, and other mechanical components[5]. Despite the increased complexity of the electrically powered typewriters, such as the IBM Selectrics, there was less down time to do repairs as the type bars were replaced with a more reliable type-ball system, reducing jams. All of these features ultimately led to a typewriter that was simple to use, reliable, and more comfortable for the operator.

Typewriters of this era began to incorporate automatic correction mechanisms, consisting of a white cover-up ribbon to overwrite mistakes without using erasers or manual intervention.

As a result of the increased complexity and cost of electric typewriters, new fields needed to be created in order to maintain them. Typewriter repair and service industries blossomed with the typewriter[4]. New models expressing new technology provided markets for diverse replacement supplies such as ribbon and correctable tape.

Single-Element Typewriters
Manual typewriters always faced the possibility of an operator pressing two keys simultaneously, jamming the typebars. Electric typewriters (electrically powered, essentially mechanical) prevent this, but the ideal situation is a single type-element that contains all of the characters needed. The first of these typewriters was the IBM Selectric, introduced in the late 1960s. The characters were positioned across the surface of a polycarbonate sphere.

The complexity needed to mechanically twist and tilt the sphere was unseemly, and repairmen were highly specialized in their training. This became the best-selling typewriter for two decades, and led to two variants[5].

After electronic circuitry and miniature actuators developed further, typewriters could be fully electronically controlled and operated. These final typewriters (which are still in production today) are electronic devices with few moving parts, and an electronic keyboard not unlike that of a computer[8].