| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 11 |
| # | Industry | |
|---|---|---|
| #1 | Civil engineering | |
| #2 | Materials and metallurgy | |
| #3 | Basic materials chemistry |
| # | Technology | |
|---|---|---|
| #1 | Earth drilling | |
| #2 | Materials for miscellaneous applications | |
| #3 | Metal production and refining | |
| #4 | Compounds containing metals |
| # | Name | Total Patents |
|---|---|---|
| #1 | Copelin Leonard S | 11 |
| Publication | Filing date | Title |
|---|---|---|
| US2189057A | Core drill | |
| US2039520A | Core drill | |
| US2070001A | Rotary core bit | |
| US1773171A | Rotary core drill | |
| US1775889A | Core-drill construction | |
| US1801265A | Expanding rotary underreamer | |
| US1766108A | Reciprocating core drill | |
| US1599810A | Core drill | |
| US1411164A | Rotary mud | |
| US1392745A | Method of recovering vanadium from solutions | |
| US1381802A | Method for recovering vanadium |