| # | Country | Total Patents | |
|---|---|---|---|
| #1 | France | 3 | |
| #2 | Germany | 2 | |
| #3 | Denmark | 2 | |
| #4 | Finland | 2 | |
| #5 | United Kingdom | 2 | |
| #6 | Austria | 1 | |
| #7 | Brazil | 1 | |
| #8 | Switzerland | 1 | |
| #9 | Hungary | 1 | |
| #10 | Japan | 1 | |
| #11 | United States | 1 |
| # | Industry | |
|---|---|---|
| #1 | Machine tools | |
| #2 | Machines | |
| #3 | Civil engineering |
| # | Technology | |
|---|---|---|
| #1 | Making metal sheets | |
| #2 | Punching metal | |
| #3 | Unspecified technologies | |
| #4 | General building constructions |
| # | Name | Total Patents |
|---|---|---|
| #1 | Markov Ivan Kirilov | 9 |
| #2 | Pejtschev Georgi Vassilev | 7 |
| #3 | Petrov Radoslav Stanev | 7 |
| #4 | Sachariev Stefan Elenkov | 7 |
| #5 | Petrov Radoslav Stanev Dipl In | 2 |
| #6 | Nikolov Kiril Amerikanov | 2 |
| #7 | Ivanov Ivan B | 2 |
| #8 | Nikolov Kiril Amerikanov Dipl | 2 |
| #9 | Peychev Georgi Vassilev | 2 |
| #10 | Zahariev Stefan Elenkov | 2 |
| Publication | Filing date | Title |
|---|---|---|
| GB1559699A | Hanging prestressed roof structurs | |
| GB1499930A | Device for changing the profile of a thin-walled metal pipe | |
| HU170954B | Apparatus for producing thin-walled metal tubes having folded seam | |
| DE2535324A1 | Metal tube production machine - has bed plate with guide, profiling block, and reduction gear at opposite ends | |
| CH607690A5 | Apparatus for the production of a thin-walled metal tube with a helical seamed joint | |
| ATA602875A | Device for manufacturing a threaded shaft folded seam, thin-walled metal tubes from a strip material |