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:
Jul. 23, 1985
Filed:
Dec. 07, 1983
Mitsui Kensetsu Kabushiki Kaisha, Tokyo, JP;
Abstract
A shield driving apparatus and process for enlarging the periphery of a predetermined region of an existing tunnel lined with a primary shield segment assembly wherein some segments of such a region of the primary shield segment assembly that correspond to the predetermined region to be enlarged are removed in series along the axial direction of the existing tunnel. The exposed ground resulting from the removal of the primary shield segment assembly is excavated to form a cavity therein. A circumferentially driving shield machine is positioned in the cavity and is mounted to bridge between the two guide rings provided at both end portions of the predetermined region and along the periphery of the existing tunnel. Circumferential segments are mounted to bridge between the two rings and are fixedly pile one upon another on the rear surface of the shield machine so as to form a series thereof connected to the shield machine while the shield machine is driven forward step by step in the circumferential direction of the existing tunnel along on the guide rings by applying a pressure to the rearmost one of the piled circumferential segments progressively formed. The enlargement of the periphery of the predetermined region lined with a ring of a series of circumferential segments is thus completed.