Average Co-Inventor Count = 1.50
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. Norton Christensen, Inc. (1 from 37 patents)
2. Spiral Drilling Systems, Inc. (1 from 1 patent)
2 patents:
1. 4904228 - Universal ball joint
2. 4552232 - Drill-bit with full offset cutter bodies