Average Co-Inventor Count = 1.33
ph-index = 2
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 (2 from 277 patents)
2 patents:
1. 4287954 - Subsurface safety valve
2. 4249599 - Well safety system