| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Denmark | 7 | |
| #2 | Austria | 3 | |
| #3 | United Kingdom | 3 | |
| #4 | United States | 3 | |
| #5 | Switzerland | 1 |
| # | Industry | |
|---|---|---|
| #1 | Machines | |
| #2 | Civil engineering | |
| #3 | Machine tools |
| # | Technology | |
|---|---|---|
| #1 | Unspecified technologies | |
| #2 | Locks | |
| #3 | Tools for connecting or disengaging |
| # | Name | Total Patents |
|---|---|---|
| #1 | Petersen Axel | 17 |
| Publication | Filing date | Title |
|---|---|---|
| US1046638A | Valve-spring compressor. | |
| GB190417432A | Improvements in Door Locks. | |
| GB190115142A | Improvements in Locks. | |
| US681372A | Lock. | |
| US664674A | Lock. | |
| GB190007613A | Improvements in Locks. |