Average Co-Inventor Count = 2.40
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. Hydril Company (4 from 277 patents)
4 patents:
1. 4635678 - Flow control apparatus
2. 4605195 - Annular blowout preventer packing unit
3. 4444250 - Flow diverter
4. 4342330 - Ball type valve having improved redundant sealing system