Average Co-Inventor Count = 3.83
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. Otis Engineering Corporation (3 from 461 patents)
3 patents:
1. 4461353 - Well safety valve
2. 4452311 - Equalizing means for well tools
3. 4448216 - Subsurface safety valve