Average Co-Inventor Count = 4.00
ph-index = 1
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. Sumitomo Metal Industries, Inc. (1 from 929 patents)
2. Railway Technical Research Institute (1 from 65 patents)
1 patent:
1. 5887788 - Steel pipe connector of ladder-type sleeper for railway track