Average Co-Inventor Count = 5.46
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. Hakusan Seisakusho Co., Ltd. (1 from 4 patents)
3. Kyushu Tetsudo Kiki Seizo Co., Ltd. (1 from 1 patent)
4. Kyushu Tetsudo Kiki Mfg., Co., Ltd. (1 from 1 patent)
2 patents:
1. 4556164 - Method of field welding head-hardened rails
2. 4520756 - Build-up spraying apparatus