Average Co-Inventor Count = 2.08
ph-index = 7
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 (9 from 277 patents)
9 patents:
1. 5713581 - Fibrous seal for blowout preventer
2. 5542454 - Free flow low energy pipe protector
3. 5465759 - Variable diameter pipe protector
4. 5430087 - Carbon black pair with different particle size and improved rubber stock
5. 5364064 - Safety sub with asymmetrical wall elastomeric closure for retaining
6. 5339864 - Safety sub for retaining drilling fluids
7. 5294253 - Carbon black system and improved rubber stock
8. 5180137 - Ram type blowout preventer having improved ram front packings
9. 5100950 - Rubber and fluorocarbon micropowder composition