A ballpoint pen is a writing instrument, more specifically a pen, similar to a pencil in size and shape. The pens have an internal chamber filled with a viscous ink that is dispensed at the tip during use by the rolling action of a small metal sphere (0.7 mm to 1 mm in diameter); the ink dries almost immediately after contact with paper. Inexpensive, reliable and maintenance-free, they have largely replaced the fountain pen.

History

Slavoljub Eduard Penkala (April 20, 1871 - February 5, 1922) was an engineer and inventor from Croatia. His inventions of the first mechanical pencil (1906) (then called "automatic pencil") and the first solid-ink fountain pen (1907). Together with an enterpreneur by the name of Edmund Moster, he started a factory of pens and pencils "Penkala-Moster" that was one of the bigger in the world at the time, and still exists today (named "TOZ-Penkala", where TOZ stood for "Tvornica olovaka Zagreb", meaning "Zagreb pencil factory").

In 1938 Laszlo Biro commercialized the pen, when he noticed that the ink used in newspaper printing dried quickly, leaving the paper dry and smudge-free. He tried using the same ink in a fountain pen but found that it would not flow into the nib, as it was too viscous. Working with his brother Georg, a chemist, he developed a new tip consisting of a ball that was free to turn in a socket, and as it turned it would pick up ink from a cartridge and then roll to deposit it on the paper. An earlier patent on the same basic idea, dated 1888, was unused and expired. In addition, it has been argued that a design, by Galileo (during the 17th century), was that of a ballpoint pen.

In 1943 the brothers moved to Argentina and on June 10 filed another patent, and formed Biro Pens of Argentina. This new design was licensed by the British, who produced ball point pens for RAF aircrew, who found they worked much better than fountain pens at high altitude. In many countries (notably several European countries, Australia, and New Zealand), ball point pens are still widely referred to as biros .

Eversharp, a maker of mechanical pencils teamed up with Eberhard-Faber in May 1945 to license the design for sales in the United States. At about the same time a US businessman saw a Biro pen in a store in Buenos Aires. He purchased several samples and returned to the U.S. to found the Reynolds International Pen Company, producing the Biro design without license as the Reynolds Rocket. He managed to beat Eversharp to market in late 1945; the first ballpoint pens went on sale at Gimbel's Department Store in New York City on October 29, 1945 for US$12.50 each. This pen was widely known as the rocket in the U.S. into the late 1950s.

Similar pens went on sale before the end of the year in England, and by the next year in most of Europe. Cheap disposable instruments were produced by the BIC Corporation with "Bic" as the tradename—now that is a common name for a ballpoint pen.

Description

There are two basic types of ball point pen: disposable and refillable.

Disposable pens are chiefly made of plastic throughout and discarded when the ink is consumed; refillable pens are metal or plastic and tend to be higher in quality and price. The refill tends to replace the entire internal ink reservoir and ball point unit rather than actually refilling it with ink.

The simplest types of ball point pens have a cap to cover the tip when the pen is not in use, while others have a mechanism for retracting the tip. This is usually controlled by a button at the top and powered by a spring within the pen apparatus, but other possibilities include a pair of buttons, a screw, or a slide.

Multi-color pens have several fillings of differently colored ink inside, and one can select which one to move from its retracted position and use. One of the most common types is a four-color pen with the colors black, red, blue, and green.

Early pens were notorious for leaking, but changes to the composition of the ink have largely made this a thing of the past. The major change was to include additives that make the ink normally much more viscous, but thin out under pressure. The pressure of the ball inside the socket starts the ink flowing, but when the pen is lifted the pressure drops and the ink thickens again.

The most recent developments in the technology include:

Multi-color pens, with multiple ink refills and ballpoints which are switchable at will. This type of pen was first introduced by Bic in the 1970s;

Rollerball pens, which combine the ballpoint design with the use of liquid ink and flow systems from fountain pens;

"Space Pens," developed by Fisher in the United States, which combine a more viscous than normal ballpoint pen ink with a gas pressurized piston which forces the ink toward the point. This design allows the pen to write even upside down or in zero gravity environments. It was designed for the use of NASA, and has since been used in both American and Russian spaceflight. Fisher has capitalized on the design, developing a line of "Space Pens" for consumer use.