Average Co-Inventor Count = 3.00
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. Japanese National Railways (2 from 50 patents)
2. Ishikawajima-Harima Jukogyo Kabushiki Kaisha (1 from 306 patents)
3. Kyokuto Boeki Kaisha, Ltd. (1 from 3 patents)
2 patents:
1. 4166509 - Process for excavating and constructing tunnel and excavating device
2. 4139320 - Process for excavating and constructing tunnel and excavating device