| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 12 |
| # | Industry | |
|---|---|---|
| #1 | Chemical engineering | |
| #2 | Machines | |
| #3 | Control | |
| #4 | Environmental technology | |
| #5 | Packaging and shipping | |
| #6 | Mechanical elements |
| # | Name | Total Patents |
|---|---|---|
| #1 | Leopold Frederick B | 12 |
| Publication | Filing date | Title |
|---|---|---|
| US1572398A | Filtering apparatus | |
| US1578669A | Multiple operating valve | |
| US1537123A | Dry-feed machine | |
| US1276665A | Manifold for filters. | |
| US992888A | Controller for filters. | |
| US1175067A | Proportional feed device for filters. | |
| US983298A | Trough for filters. | |
| US983297A | Sluice-gate. | |
| US964528A | Inlet-controller for liquids. | |
| US980538A | Nozzle. | |
| US829113A | Washtrough for filters. | |
| US829021A | Filter-table. |