Average Co-Inventor Count = 3.62
ph-index = 8
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 (6 from 461 patents)
2. Halliburton Energy Services, Inc. (3 from 11,766 patents)
9 patents:
1. 8047294 - Dual flapper safety valve
2. 7798229 - Dual flapper safety valve
3. 6302210 - Safety valve utilizing an isolation valve and method of using the same
4. 4834183 - Surface controlled subsurface safety valve
5. 4723606 - Surface controlled subsurface safety valve
6. 4469179 - Safety system
7. 4461353 - Well safety valve
8. 4452311 - Equalizing means for well tools
9. 4448216 - Subsurface safety valve