Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6820417 | Exhaust aftertreatment system and method for an internal combustion engine | David F. May, Charles R. Schenk, H. Lee Fisher, Angela R. May | 2004-11-23 |
| 6668663 | Method and apparatus to determine flow rate with the introduction of ambient air | David F. May, Angela R. May | 2003-12-30 |
| 6579218 | Centrifugal filter utilizing a partial vacuum condition to effect reduced air drag on the centrifuge rotor | David F. May, Steven J. Merritt | 2003-06-17 |
| 6517475 | Centrifugal filter for removing soot from engine oil | Gene W. Brown, Steven J. Merritt, Farrell F. Calcaterra, John H. Beard, David F. May | 2003-02-11 |