Issued Patents All Time
Showing 101–117 of 117 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5035292 | Whipstock starter mill with pressure drop tattletale | John E. Campbell, Edmond Kagler, Jr. | 1991-07-30 |
| 5022472 | Hydraulic clamp for rotary drilling head | John E. Campbell | 1991-06-11 |
| 5009265 | Packer for wellhead repair unit | Charles E. Lancaster, Richard Lee | 1991-04-23 |
| 4984636 | Geothermal wellhead repair unit | James N. Strickland | 1991-01-15 |
| 4962819 | Mud saver valve with replaceable inner sleeve | Raymond A. Todd, Jr. | 1990-10-16 |
| 4955949 | Mud saver valve with increased flow check valve | Raymond A. Todd, Jr. | 1990-09-11 |
| 4865137 | Drilling apparatus and cutter | John E. Campbell | 1989-09-12 |
| 4804026 | Self-supporting funnel | — | 1989-02-14 |
| 4765404 | Whipstock packer assembly | John E. Campbell | 1988-08-23 |
| 4759413 | Method and apparatus for setting an underwater drilling system | John E. Campbell | 1988-07-26 |
| 4722615 | Drilling apparatus and cutter therefor | John E. Campbell | 1988-02-02 |
| 4660863 | Casing patch seal | Nehal Shah | 1987-04-28 |
| 4646826 | Well string cutting apparatus | John E. Campbell, Nehal Shah | 1987-03-03 |
| 4575426 | Method and apparatus employing oleophilic brushes for oil spill clean-up | Lee A. Littlejohn, Keith F. Kruk, Robert E. Williams | 1986-03-11 |
| 4533003 | Drilling apparatus and cutter therefor | John E. Campbell, Allen Kent Rives, Nehal Shah | 1985-08-06 |
| 4336840 | Double cylinder system | — | 1982-06-29 |
| 4249600 | Double cylinder system | — | 1981-02-10 |