Inventions during 1900 to 1940 A.D By Pushpendra

BALL POINT PEN (1888-1935): American John Loud invents the ballpoint pen but it is not produced commercially until 1935. A ball point pen is a pen which dispense ink over a metal ball at its point . The metals commonly used in making metal ball are steel , brass and tungsten. The design was conceived and developed as a cleaner and more reliable alternative to dip pen and fountain pen , and it is now the world's most-used writing instrument millions are manufactured and sold daily. Ballpoint pen ink is normally a paste containing around 25 to 40 percent dye. The dyes are suspended in a mixture of solvents and fatty acids. The most common of the solvents are benzyl alcohol or phenoxyethanol, which mix with the dyes and oils to create a smooth paste that dries quickly. Ball point pen are mainly manufactured in two types disposable and refillable. Refills allow for the entire internal ink reservoir, including a ballpoint and socket, to be replace...