| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 6 | |
| #2 | Switzerland | 3 | |
| #3 | Denmark | 3 | |
| #4 | Austria | 2 | |
| #5 | United States | 2 | |
| #6 | France | 1 |
| # | Industry | |
|---|---|---|
| #1 | Consumer goods |
| # | Technology | |
|---|---|---|
| #1 | Writing or drawing tools |
| # | Name | Total Patents |
|---|---|---|
| #1 | Wilhelm Grube | 4 |
| #2 | Grube Dr Friedrich Otto | 1 |
| #3 | Grube Wilhelm | 1 |
| #4 | Woringen Heinrich | 1 |
| #5 | Pol Grube Friedrich Dr Rer | 1 |
| #6 | Grube Dipl-Kfm Wilhelm | 1 |
| #7 | Nitzsche Robert | 1 |
| #8 | Friedrich Grube Kaweco Badisch | 1 |
| #9 | Friedrich Grube | 1 |
| #10 | Grube Friedrich | 1 |
| Publication | Filing date | Title |
|---|---|---|
| DE1236975B | Replaceable refill for ballpoint pen | |
| DE1156000B | Retractable ballpoint pen with a refill arranged at an acute angle to the longitudinal axis of the holder | |
| US2972335A | Reversible ink cartridge unit for ball point pens | |
| DE894217C | Clip for fountain pen u. like | |
| DE832720C | Ballpoint pen with ink filling | |
| DE718495C | Mechanical pencil with two lead clamp pliers | |
| DE625889C | Ink feed for fountain pen |