Patents per Year
Top Inventors at Grefco All Time
Showing 1–9 of 9 inventors
| Rank | Name | Patents |
|---|---|---|
| 1 | David L. Ruff | 3 |
| 1 | Richard B. Nielsen | 3 |
| 3 | N. Gokul Nath | 2 |
| #4 | Albert Collins | 1 |
| #4 | Charles J. Vogelsang | 1 |
| #4 | Harlan E. Tarbell | 1 |
| #4 | Melvin J. Mirliss | 1 |
| #4 | Narikottile G. Nath | 1 |
| #4 | William R. White | 1 |
Most Valuable Patents
| Patent | Est. Value | Year |
|---|---|---|
| Method for the treatment of mineral extender fillers | $635K | 1987 |
| Method and apparatus for heating particulate material | $612K | 1985 |
| Perlite filler coated with polydimethylsiloxane | $456K | 1980 |
| Diatomaceous earth filteraid and method for its manufacture | $425K | 1980 |
| Perlite filler | $308K | 1981 |