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:
Jun. 20, 1978
Filed:
Mar. 21, 1977
Herbert Heitkamp, Werne, DT;
Rolf Stoltz, Bottrop, DT;
Gewerkschaft Eisenhutte Westfalia, Lunen, DT;
Abstract
Apparatus is provided for controlling the advance of a tunnel drive shield. The drive shield is of the type having a plurality of elongate implements (or planks) which are supported and guided on a frame. Hydraulic rams are provided for moving the planks relative to the frame. The control apparatus comprises hydraulic ram means, which act between the frame and the permanent tunnel lining, and means for varying the pressure of hydraulic fluid applied to said hydraulic ram means. The frame can be advanced by applying hydraulic fluid to said hydraulic ram means and by simultaneously applying hydraulic fluid to at least one of said hydraulic rams. The direction of frame advance is controlled by varying the ratio of the pressures of the hydraulic fluid applied to said hydraulic ram means and to said at least one hydraulic ram.