Inventor · State College, PA, US

John R. Hellmann

5Patents
3h-index
9Co-inventors
50Inventor score

Filing activity: Aug 20, 1991 → Jan 17, 2013

Most-cited inventions

PatentTitleAreaCited byStatus
US8193128B2 Treatment of particles for improved performance as proppants Chemistry; Metallurgy 31 Active
US5220824A High temperature, tube burst test apparatus Physics 9 Expired
US7828998B2 Material having a controlled microstructure, core-shell macrostructure, and method for its fabrication Chemistry; Metallurgy 5 Active
US8959954B2 Proppants from mineralogical material Chemistry; Metallurgy 2 Active
US8359886B2 Treatment of melt quenched aluminosilicate glass spheres for application as proppants via devitrification processes Emerging Cross-Sectional Technologies 1 Active

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.