Inventor

Friedrich Esper

18Patents
12h-index
27Co-inventors
74Inventor score

Filing activity: May 2, 1974 → May 23, 1990

Most-cited inventions

PatentTitleAreaCited byStatus
US4535487A Endoprosthesis shaft Human Necessities 51 Expired
US4334974A Electrochemical oxygen sensor, particularly for use with exhaust gases of internal combustion engines, and especially for polarographic application Physics 39 Expired
US4418661A Glow plug, particularly for diesel engine Mechanical Engineering; Lighting; Heating 36 Expired
US4221650A Solid electrolyte oxygen sensors Emerging Cross-Sectional Technologies 29 Expired
US4320080A Method to manufacture soft magnetic pressed bodies Emerging Cross-Sectional Technologies 26 Expired
US4019914A Method of manufacturing .alpha.-alumina Chemistry; Metallurgy 25 Expired
US4356571A Prosthetic device Human Necessities 23 Expired
US4268468A Method of making a medical prosthesis Performing Operations; Transporting 21 Expired
US4339320A Heated gas composition sensor structure Physics 21 Expired
US4539503A Rapid-heating, high-temperature-stable spark plug for internal combustion engines Electricity 15 Expired
US5194099A Sinter magnet based on Fe-Nd-B Chemistry; Metallurgy 14 Expired
US4183798A Stabilized zirconium dioxide compositions and oxygen sensors utilizing said compositions Chemistry; Metallurgy 12 Expired
US4128420A High-strength iron-molybdenum-nickel-phosphorus containing sintered alloy Chemistry; Metallurgy 11 Expired
US4532492A Temperature-compensated, oxygen-content gas sensor Physics 9 Expired
US4618351A Device for cleaning of gases Emerging Cross-Sectional Technologies 6 Expired
US4503348A Magnetic transducer Electricity 3 Expired
US3959002A Method of manufacturing white furnace boats for firing ceramic articles and novel furnace boats Chemistry; Metallurgy 3 Expired
US4533392A High strength sintered alloy Chemistry; Metallurgy 0 Expired

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