Average Co-Inventor Count = 1.97
ph-index = 4
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Baker Hughes Corporation (3 from 5,728 patents)
2. Eastman Christensen Company (1 from 38 patents)
4 patents:
1. 5168941 - Drilling tool for sinking wells in underground rock formations
2. 5156222 - Directional drilling tool apparatus and method
3. 5040155 - Double guided mud pulse valve
4. 4901290 - Apparatus for the generation of pressure pulses in drilling mud