Seals for tunnelling shields
US4139989A · kind A · utility
4Cited by
5References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 25, 1977 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | Jul 25, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21D9/0635
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A tail seal for a tunnelling shield, particularly for use in the bentonite process, in which a seal is formed of short brush-like material mounted on a flexible support and resiliently urged by a body of closed cell expanded material, such as neoprene. In a preferred form the flexible support is secured both fore and aft and the closed cell expanded material has an inflatable member embedded therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.