Average Co-Inventor Count = 4.44
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. Hitachi, Ltd. (2 from 42,485 patents)
2 patents:
1. 4613285 - Piston stroke control device for free piston type oscillating compressors
2. 4520634 - Multi-stage absorption refrigeration system