<P> Bíró's patent, and other early patents on ballpoint pens often used the term "ball - point fountain pen". </P> <P> Following World War II, many companies vied to commercially produce their own ballpoint pen design . In post-war Argentina, success of the Birome ballpoint was limited, but in mid-1945, the Eversharp Co., a maker of mechanical pencils, teamed up with Eberhard Faber Co. to license the rights from Birome for sales in the United States . </P> <P> During the same period, American entrepreneur Milton Reynolds came across a Birome ballpoint pen during a business trip to Buenos Aires, Argentina . Recognizing commercial potential, he purchased several ballpoint samples, returned to the United States, and founded Reynolds International Pen Company . Reynolds bypassed the Birome patent with sufficient design alterations to obtain an American patent, beating Eversharp and other competitors to introduce the pen to the U.S. market . Debuting at Gimbels department store in New York City on 29 October 1945, for US $12.50 each (1945 US dollar value, about $166 in 2016 dollars), Reynolds Rocket became the first commercially successful ballpoint pen . Reynolds went to great extremes to market the pen, with great success; Gimbel's sold many thousands of pens within one week . In Britain, the Miles Martin pen company was producing the first commercially successful ballpoint pens there by the end of 1945 . </P> <P> Neither Reynolds' nor Eversharp's ballpoint lived up to consumer expectations in America . Ballpoint pen sales peaked in 1946, and consumer interest subsequently plunged due to market - saturation . By the early 1950s the ballpoint boom had subsided and Reynolds' company folded . </P>

Who patented the first commercially successful ballpoint pen