Gerhard Zerrer
22Patents
14h-index
26Co-inventors
81Inventor score
Filing activity: Sep 20, 1974 → Oct 20, 2003
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5826478A | Nozzle for supplying a liquid to a rotating tool | Emerging Cross-Sectional Technologies | 39 | Expired |
| US4461055A | Portable sweeping device | Human Necessities | 33 | Expired |
| US4651421A | Cutterhead for a vegetation cutter | Human Necessities | 26 | Expired |
| US4285127A | Apparatus for trimming plants | Human Necessities | 26 | Expired |
| US4690252A | Rotation-preventing locking device for a portable tool | Emerging Cross-Sectional Technologies | 24 | Expired |
| US3969856A | Adjustable protective hood for a rotary tool | Emerging Cross-Sectional Technologies | 22 | Expired |
| US4866846A | Cutterhead for a vegetation cutter | Human Necessities | 21 | Expired |
| US5704257A | Securing mechanism for securing a drive shaft of a rotating tool member of a working tool | Emerging Cross-Sectional Technologies | 19 | Expired |
| US6904977B2 | Portable handheld work apparatus | Human Necessities | 19 | Expired |
| US4696108A | Pruning apparatus | Human Necessities | 18 | Expired |
| US4864728A | Brushcutter | Human Necessities | 17 | Expired |
| US5743240A | Hand-guided, portable tool with internal combustion engine | Emerging Cross-Sectional Technologies | 16 | Expired |
| US4893410A | Cutterhead for a vegetation cutter | Human Necessities | 15 | Expired |
| US4662158A | Brushcutter having a starter arrangement | Human Necessities | 14 | Expired |
| US4761939A | Brushcutter | Emerging Cross-Sectional Technologies | 13 | Expired |
| USD276662S | Portable pneumatic sweeper | General | 12 | Expired |
| US4529099A | Closure for a fuel tank | Performing Operations; Transporting | 11 | Expired |
| US4644658A | Lubricating-oil pump arrangement for a motor-driven apparatus | Emerging Cross-Sectional Technologies | 10 | Expired |
| US5887489A | Locking device for a rotary member of a working tool | Emerging Cross-Sectional Technologies | 7 | Expired |
| US5320281A | Housing for a high-pressure cleaning apparatus | Performing Operations; Transporting | 5 | Expired |
| US5267540A | Pull-rope starter for an internal combustion engine | Mechanical Engineering; Lighting; Heating | 4 | Expired |
| US4932366A | Portable handheld motor-driven tool | Mechanical Engineering; Lighting; Heating | 4 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.