Average Co-Inventor Count = 2.40
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. Varco International, Inc. (2 from 49 patents)
2 patents:
1. 4437524 - Well drilling apparatus
2. 4423645 - Pipe spinner