Inventor · Eden Prairie, MN, US

Ralph M. Hoffmann

15Patents
6h-index
6Co-inventors
59Inventor score

Filing activity: Oct 29, 1979 → Jun 17, 2014

Most-cited inventions

PatentTitleAreaCited byStatus
US4297090A Rotary expansion power unit with valve disc connected to crankshaft Mechanical Engineering; Lighting; Heating 18 Expired
US4728270A Apparatus and method for replacing apex seals in a rotary device Mechanical Engineering; Lighting; Heating 14 Expired
US4721445A Outer envelope trochoidal rotary device having a rotor assembly having peripheral reliefs Mechanical Engineering; Lighting; Heating 12 Expired
US4382755A Driveshaft arrangement for trochoidal rotary device Mechanical Engineering; Lighting; Heating 12 Expired
US5046932A Rotary epitrochoidal compressor Mechanical Engineering; Lighting; Heating 12 Expired
US4895222A Constant level oiler Physics 8 Expired
US4400145A Driveshaft arrangement for a rotary expansible chamber device Mechanical Engineering; Lighting; Heating 6 Expired
US4884661A Center-fill top cover for oilers Mechanical Engineering; Lighting; Heating 4 Expired
US9306331B2 Self-aligning connector for data and/or power transmission Electricity 3 Active
US4551083A Dual rotor gear assembly for trochoidal rotary device Mechanical Engineering; Lighting; Heating 3 Expired
US4827983A Swiveling mount for the outlet of a pressure vessel Emerging Cross-Sectional Technologies 3 Expired
US4911043A Apparatus and method for milling a trochoidal rotor Emerging Cross-Sectional Technologies 2 Expired
US4778362A Outer envelope trochoidal rotary device having a two piece rotor assembly Mechanical Engineering; Lighting; Heating 1 Expired
US4735560A Seal assembly for a rotary device Mechanical Engineering; Lighting; Heating 1 Expired
US9605472B2 Connecting means comprising a hatch and a bellows Fixed Constructions 0 Active

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