| Number | Name | Date | Kind |
|---|---|---|---|
| 3507192 | Stokke | Apr 1970 | |
| 3877529 | Litchfield | Apr 1975 | |
| 3887161 | Kubelka, Jr. | Jun 1975 | |
| 3915244 | Brown | Oct 1975 | |
| 3941348 | Mott | Mar 1976 | |
| 4170169 | Shafer | Oct 1979 | |
| 4417600 | Kohn | Nov 1983 | |
| 4421171 | Haynes | Dec 1983 | |
| 4456217 | Winegeart et al. | Jun 1984 |
| Entry |
|---|
| Hydril, "Kelleyguard", bulletin 6506. |
| International Tool Company, advertising sheet, p. 3515. |
| Varco, drawing #71840. |