The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 27, 1990
Filed:
Aug. 15, 1988
Siegmund Babendererde, Lubeck-Travemunde, DE;
Hochtief Aktiengesellschaft Vorm. Gebr. Helfmann, Essen, DE;
Abstract
In my process for digging a tunnel with the help of a tunnel excavator which has a working chamber under atmospheric pressure, the local front wall is supported with the help of a pressurized medium which is connected by a controlling gap of a shield cover with another gap between a shield cover tail and/or the earth or ground and a tunnel-lining member. The gap is closed-off from the working chamber by a gap-sealing ring between a shield cover tail and a tunnel-lining member. Concrete is forced into the gap by a feeder pipe in the gap-sealing ring. A self-sealing permeable joint between the gap-sealing ring and the shield cover tail and/or the tunnel-lining member of the excavator is made with concrete which has a fine-grained additive material and a large-grained additive material so that the large-grained additive material forms a grain filter whose pores are closable by the fine-grained additive material.