Average Co-Inventor Count = 3.00
ph-index = 3
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 (3 from 277 patents)
3 patents:
1. 4461448 - Well blowout preventer, and packing element
2. 4452421 - Well blowout preventer, and packing element
3. 4447037 - Well blowout preventer, and packing element