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.

Date of Patent:
Mar. 13, 1979

Filed:

Feb. 07, 1978
Applicant:
Inventor:

Eberhard Unger, Lunen, DE;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21D / ;
U.S. Cl.
CPC ...
405145 ;
Abstract

A drive shield for driving wide underground cavities comprises a plurality of knife shields arranged side-by-side transversely of the direction of advance. Each knife shield has a plurality of elongate knives displaceably mounted on a respective support frame. The elongate knives are advanceable relative to their support frame by means of hydraulic rams mounted on that support frame. The support frames of each pair of adjacent knife shields are linked by connecting means such as double-acting hydraulic rams, which permit one of the support frames to be advanced relative to the other.


Find Patent Forward Citations

Unger, Eberhard. (1979). Drive shield (U.S. Patent No. 4143519). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4143519

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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