Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5873157 | Field installable rod guide and method | Charles M. Hart, H. Milton Hoff, John L. Tillman, Jr., Lindell R. Trout | 1999-02-23 |
| 5845909 | Stuffing box with improved packing rings and method | Lawrence F. Angelo, J. William Heathcott | 1998-12-08 |
| 5755284 | Extended wear rod guide and method | Charles M. Hart, H. Milton Hoff, Randall Ray | 1998-05-26 |
| 5622371 | Stuffing box with improved packing rings and method | Lawrence F. Angelo, J. William Heathcott | 1997-04-22 |
| 5339896 | Field installable rod guide and method | Charles M. Hart, H. Milton Hoff, John L. Tillman, Jr., Lindell R. Trout | 1994-08-23 |
| D279170 | Loose fill packing element | — | 1985-06-11 |