John E. Campbell
64Patents
27h-index
72Co-inventors
91Inventor score
Filing activity: Jul 3, 1975 → Sep 6, 2023
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US7141853B2 | Method and structure for buried circuits and devices | Electricity | 373 | Expired |
| US6759282B2 | Method and structure for buried circuits and devices | Electricity | 304 | Expired |
| US5022472A | Hydraulic clamp for rotary drilling head | Emerging Cross-Sectional Technologies | 173 | Expired |
| US4765404A | Whipstock packer assembly | Fixed Constructions | 159 | Expired |
| US5431220A | Whipstock starter mill assembly | Fixed Constructions | 129 | Expired |
| US5154231A | Whipstock assembly with hydraulically set anchor | Fixed Constructions | 116 | Expired |
| US5035292A | Whipstock starter mill with pressure drop tattletale | Fixed Constructions | 82 | Expired |
| US5530753A | Methods and apparatus for secure hardware configuration | Electricity | 76 | Expired |
| US5829531A | Mechanical set anchor with slips pocket | Fixed Constructions | 75 | Expired |
| US4646826A | Well string cutting apparatus | Fixed Constructions | 74 | Expired |
| US5365587A | Self modifying access code for altering capabilities | Electricity | 73 | Expired |
| US5657820A | Two trip window cutting system | Fixed Constructions | 69 | Expired |
| US5213158A | Dual rotating stripper rubber drilling head | Fixed Constructions | 68 | Expired |
| US4759413A | Method and apparatus for setting an underwater drilling system | Fixed Constructions | 65 | Expired |
| US5348107A | Pressure balanced inner chamber of a drilling head | Mechanical Engineering; Lighting; Heating | 64 | Expired |
| US5062450A | Valve body for oilfield applications | Emerging Cross-Sectional Technologies | 63 | Expired |
| US5878818A | Mechanical set anchor with slips pocket | Fixed Constructions | 60 | Expired |
| US5048621A | Adjustable bent housing for controlled directional drilling | Fixed Constructions | 59 | Expired |
| US4865137A | Drilling apparatus and cutter | Fixed Constructions | 52 | Expired |
| US5427179A | Retrievable whipstock | Fixed Constructions | 51 | Expired |
| US4722615A | Drilling apparatus and cutter therefor | Mechanical Engineering; Lighting; Heating | 50 | Expired |
| US4533003A | Drilling apparatus and cutter therefor | Fixed Constructions | 47 | Expired |
| US5530749A | Methods and apparatus for secure hardware configuration | Electricity | 46 | Expired |
| US5082020A | Valve body for oilfield applications | Emerging Cross-Sectional Technologies | 35 | Expired |
| US7506703B2 | Drilling and hole enlargement device | Fixed Constructions | 34 | Active |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.