Average Co-Inventor Count = 1.33
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. Hochtief Aktiengesellschaft Vorm. Gebr.helfmann (3 from 27 patents)
2. Bade & Theelen Gmbh (1 from 1 patent)
3 patents:
1. 4436448 - Excavating machine for tunnels and galleries
2. 4264542 - Method of lining tunneled tubes
3. 4209338 - Concrete for the lining of tunnel tubes