| # | Industry | |
|---|---|---|
| #1 | Machines | |
| #2 | Machine tools | |
| #3 | Chemical engineering | |
| #4 | Engines, pumps and turbines | |
| #5 | Mechanical elements |
| # | Technology | |
|---|---|---|
| #1 | Producing goods from plastic | |
| #2 | Wood working | |
| #3 | Rotary pistons | |
| #4 | Pistons and sealings | |
| #5 | Separating solids | |
| #6 | Grinding or polishing devices | |
| #7 | Tools for connecting or disengaging |
| Publication | Filing date | Title |
|---|---|---|
| DE467211C | Device for sorting raw stone nut slices, button washers or buttons of various sizes | |
| DE475309C | Device for the automatic insertion of button washers in the chucks of automatic button machines | |
| DE457141C | Device for automatic turning of buttons of the same size | |
| DE407132C | Button drilling machine | |
| DE425735C | Machine for polishing buttons | |
| DE362093C | Multi-spindle button drilling machine |