Sealing means for the drive members of drive shields

US4155668A · kind A · utility

Assignee

• Gewerkschaft Eisenhutte Westfalia GmbH · DE

Inventors

• Herbert Heitkamp · Werne, DE
• Dieter Stuckmann · Selm, DE

Key dates

• Filing date: Feb 24, 1978
• Grant date: May 22, 1979
• Expiry date: Feb 24, 1998

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21D11/385
• WIPO field: Civil engineering
• WIPO sector: Other fields

Abstract

The drive members of a drive shield, which are mounted side-by-side for longitudinal displacement as is known per se, are provided with seals or packings to close off the gaps between adjacent members. Each seal or packing is composed of two flexible resilient parts joined to respective drive members. The seal parts slidably engage one another in sealing fashion. The parts of the seal may be of the same or disimilar shape but at least one of the parts is hollow with an interior cavity which can receive pressure medium used to expand the part to urge the contacting surfaces of the parts into close sealing contact. Lubrication between the contacting surfaces to permit sliding can be achieved by employing a suitable lubricating agent as, or in, the pressure medium and by allowing some of the pressure medium to pass from the interior cavity to the contacting surfaces.