Christensen, Inc.
48Patents
0Active
48Granted
37Portfolio score
Filing activity: Jan 21, 1976 → Dec 29, 1983
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4429741A | Self powered downhole tool anchor | Fixed Constructions | 171 | Expired |
| US4373593A | Drill bit | Emerging Cross-Sectional Technologies | 145 | Expired |
| US4351401A | Earth-boring drill bits | Fixed Constructions | 143 | Expired |
| US4200159A | Cutter head, drill bit and similar drilling tools | Fixed Constructions | 129 | Expired |
| US4460053A | Drill tool for deep wells | Fixed Constructions | 92 | Expired |
| US4073354A | Earth-boring drill bits | Fixed Constructions | 82 | Expired |
| US4266621A | Well casing window mill | Fixed Constructions | 79 | Expired |
| US4471845A | Rotary drill bit | Fixed Constructions | 69 | Expired |
| US4352400A | Drill bit | Fixed Constructions | 59 | Expired |
| US4512426A | Rotating bits including a plurality of types of preferential cutting elements | Emerging Cross-Sectional Technologies | 57 | Expired |
| US4244432A | Earth-boring drill bits | Fixed Constructions | 54 | Expired |
| US4499959A | Tooth configuration for an earth boring bit | Fixed Constructions | 50 | Expired |
| US4468762A | Telemetry equipment in modules | Fixed Constructions | 49 | Expired |
| US4098363A | Diamond drilling bit for soft and medium hard formations | Fixed Constructions | 48 | Expired |
| US4231437A | Combined stabilizer and reamer for drilling well bores | Fixed Constructions | 44 | Expired |
| US4133516A | Shock absorber for well drilling pipe | Fixed Constructions | 42 | Expired |
| US4092881A | Apparatus for making-up and breaking threaded pipe connections | Emerging Cross-Sectional Technologies | 41 | Expired |
| US4234048A | Drill bits embodying impregnated segments | Fixed Constructions | 40 | Expired |
| US4515227A | Nozzle placement in a diamond rotating bit including a pilot bit | Fixed Constructions | 39 | Expired |
| US4452324A | Rotary drill bit | Fixed Constructions | 38 | Expired |
| US4270569A | Valve assembly for the remote control of fluid flow having an automatic time delay | Emerging Cross-Sectional Technologies | 37 | Expired |
| US4415316A | Down hole motor | Emerging Cross-Sectional Technologies | 36 | Expired |
| US4186569A | Dual spring drill string shock absorber | Fixed Constructions | 35 | Expired |
| US4194582A | Double acting shock absorbers for drill strings | Fixed Constructions | 32 | Expired |
| US4245709A | Removable drill string stabilizers | Emerging Cross-Sectional Technologies | 30 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.