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. Dyckerhoff & Widmann Aktiengesellschaft (2 from 104 patents)
2 patents:
1. 5135164 - Prestressed concrete railroad tie
2. 4905896 - Railroad roadway for high speed rail-mounted vehicles