-
-
-
-
-
-
-
-
-
-
-
-
Shield tunneling machine
-
Patent number 4,655,493
-
Issue date Apr 7, 1987
-
Kabushiki Kaisha Iseki Kaihatsu Koki
-
Toshio Sumi
-
E21 - EARTH DRILLING MINING
-
-
Tunneling machine
-
Patent number 4,627,765
-
Issue date Dec 9, 1986
-
Hochtief Aktiengesellschaft Vorm. Gebr. Helfmann
-
Volker Hentschel
-
E21 - EARTH DRILLING MINING
-
Shield tunneling apparatus
-
Patent number 4,624,605
-
Issue date Nov 25, 1986
-
Kabushiki Kaisha Iseki Kaihatsu Koki
-
Toshio Akesaka
-
E21 - EARTH DRILLING MINING
-
-
Tunnel drive shield
-
Patent number 4,122,683
-
Issue date Oct 31, 1978
-
Gewerkschaft Eisenhutte Westfalia
-
Hans G. Follert
-
E21 - EARTH DRILLING MINING
-
-
Tunnelling shields
-
Patent number 3,955,373
-
Issue date May 11, 1976
-
Stelmo Limited
-
Kenneth Gilbert Jessop
-
E21 - EARTH DRILLING MINING
-
3763657
-
Patent number 3,763,657
-
Issue date Oct 9, 1973
-
E21 - EARTH DRILLING MINING
-
3733835
-
Patent number 3,733,835
-
Issue date May 22, 1973
-
E21 - EARTH DRILLING MINING
-
3613384
-
Patent number 3,613,384
-
Issue date Oct 19, 1971
-
E21 - EARTH DRILLING MINING
-
3266257
-
Patent number 3,266,257
-
Issue date Aug 16, 1966
-
E21 - EARTH DRILLING MINING
-
2139563
-
Patent number 2,139,563
-
Issue date Dec 6, 1938
-
E21 - EARTH DRILLING MINING
-
1917170
-
Patent number 1,917,170
-
Issue date Jul 4, 1933
-
E21 - EARTH DRILLING MINING
-
1355290
-
Patent number 1,355,290
-
Issue date Oct 12, 1920
-
E21 - EARTH DRILLING MINING
-
1256313
-
Patent number 1,256,313
-
Issue date Feb 12, 1918
-
E21 - EARTH DRILLING MINING
-
1173158
-
Patent number 1,173,158
-
Issue date Feb 29, 1916
-
E21 - EARTH DRILLING MINING
-
748809
-
Patent number 748,809
-
Issue date Jan 5, 1904
-
E21 - EARTH DRILLING MINING
-
675355
-
Patent number 675,355
-
Issue date May 28, 1901
-
E21 - EARTH DRILLING MINING