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:
Feb. 09, 1993
Filed:
Sep. 24, 1991
Herrenknecht GmbH, Schwanau, DE;
Abstract
The tunnelling machine for driving inaccessible tunnels by pressing forward by means of tubes can be moved out again through the tunnel driven by it. For this purpose, an annular outer area (2b) is provided on the extracting tool (2), and one double casing (4b, 6b) each is provided around the control head (4) and the machine tube (6). The outer area (2b) of the extracting tool is connected to its inner area (2a) and the control-head double casing (4b) is connected to the control-head housing (4a) by connecting elements (24, 26). Specifically releasable restraining devices (28) hold the machine-tube double casing (6b) on the machine-tube housing (6a). After the final depth is reached, the control head (4) can be moved back by means of the control devices (40) to such an extent towards the machine tube (6) that the connecting elements (24, 26) are broken. If the restraining devices (28) are then released, the tunnelling machine is separated from the extracting-tool outer area (2b) and the double casings (4b, 6b) and can be withdrawn at withdrawal means (42) provided for this purpose, whereby the tunnelling machine may be recovered for reuse in a simple manner even from tunnels which do not end in a target shaft.