Title:
Apparatus for driving and lining tunnels in unstable soil
United States Patent 3350889
US Patent References:
/0360959.html
- - 0360959
/0428021.html
- - 0428021
/0438509.html
- - 0438509
/0512037.html
- - 0512037
/0748809.html
- - 0748809
/0360959.html
- - 0360959
/0428021.html
- - 0428021
/0438509.html
- - 0438509
/0512037.html
- - 0512037
/0748809.html
- - 0748809
Inventors:
Karl, Sturm
Publication Date:
11/07/1967
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Export Citation:
Assignee:
Karl, Sturm
Primary Class:
Other Classes:
299/56, 405/150.100, 405/146, 299/33, 405/144
International Classes:
E21D9/08; E21D9/13; E21D9/06; E21D9/12
US Patent References:
Foreign References:
| DE620764C | ||||
| GB443158A |