Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 10214966 | Rotary drill bits with back-up cutting elements to optimize bit life | Shilin Chen, Robert W. Arfele, James R. Ashby | 2019-02-26 |
| 9677341 | Drill bit with extended life seal | Seth Garrett Anderle, Ping Sui, Mark E. Williams | 2017-06-13 |
| 6752223 | Roller cone bit with improved seal gland design | Amiya K. Panigrahi, Mark P. Blackman | 2004-06-22 |
| 6279671 | Roller cone bit with improved seal gland design | Amiya K. Panigrahi, Mark P. Blackman | 2001-08-28 |