<sod>In 1945 [[Marcel Bich]] bought the patent from Bíró for the pen, which soon became the main product of his [[Société Bic|Bic]] company, which has sold more than 100 billion ballpoint pens worldwide. In November of that same year, promoter [[Milton Reynolds]] introduced a gravity-fed pen to the U.S. market. The Reynolds Pen was a sensation for a few years, until its reputation for leaking and competition from established pen manufacturers overtook it. Bíró's patent was based on [[capillary action]], which caused ink to be drawn out of the pen as it was deposited on the paper. Because the Reynolds workaround depended on gravity, which cannot be patented, it did not infringe but required thinner ink and a larger barrel.<ref>Rosenberg, Robert Leonard, "The Ventures and Adventures of an Errant Entrepreneur". Milton (Ball-Point) Reynolds (1892–1976), University of Washington Ph.D. thesis (1971), Milton Reynolds papers http://www.lib.washington.edu/specialcoll/findaids/docs/papersrecords/ReynoldsMilton1240.xml.</ref><eod>
<sod>In 1945 [[Marcel Bich]] bought the patent from Bíró for the pen, which soon became the main product of his [[Société Bic|Bic]] company, which has sold more than 100 billion ballpoint pens worldwide. In November of that same year, promoter [[Milton Reynolds]] introduced a gravity-fed pen to the U.S. market. The Reynolds Pen was a sensation for a few years, until its reputation for leaking and competition from established pen manufacturers overtook it. Bíró's patent was based on [[capillary action]], which caused ink to be drawn out of the pen as it was deposited on the paper. Because the Reynolds workaround depended on gravity, it did not infringe but required thinner ink and a larger barrel.<ref>Rosenberg, Robert Leonard, "The Ventures and Adventures of an Errant Entrepreneur". Milton (Ball-Point) Reynolds (1892–1976), University of Washington Ph.D. thesis (1971), Milton Reynolds papers http://www.lib.washington.edu/specialcoll/findaids/docs/papersrecords/ReynoldsMilton1240.xml.</ref><eod>