| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 3 | |
| #2 | Canada | 2 | |
| #3 | EPO (European Patent Office) | 2 | |
| #4 | Australia | 1 | |
| #5 | Norway | 1 | |
| #6 | New Zealand | 1 | |
| #7 | Taiwan | 1 |
| # | Industry | |
|---|---|---|
| #1 | Civil engineering | |
| #2 | Transport |
| # | Technology | |
|---|---|---|
| #1 | Foundations and excavations | |
| #2 | Earth drilling | |
| #3 | Hand carts |
| # | Name | Total Patents |
|---|---|---|
| #1 | Henke Robert | 9 |
| #2 | Henke Wanda K | 7 |
| #3 | Henke Wanda Kelly | 1 |
| #4 | Lang Frederick | 1 |
| Publication | Filing date | Title |
|---|---|---|
| US5203824A | Method and apparatus for preparing the surface of a region of soil for further testing | |
| US4594899A | Method and apparatus for testing soil | |
| US887821A | Hand-truck. |