Average Co-Inventor Count = 5.71
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. Qiqihar Railway Rolling Stock Co., Ltd. (3 from 14 patents)
3 patents:
1. 9061688 - Bottom door device and hopper car having the same
2. 8950340 - Ballast hopper car discharge door control system
3. 8939088 - Bottom door opening-closing mechanism, bottom door device and drop-bottom hopper car