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:
Sep. 23, 1980
Filed:
Aug. 14, 1978
Applicant:
Inventor:
Herbert Heitkamp, Werne, DE;
Assignee:
Gewerkschaft Eisenhutte Westfalia, Lunen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E01G / ; E21D / ;
U.S. Cl.
CPC ...
405145 ; 175 61 ; 175 73 ; 299 31 ; 405141 ;
Abstract
A knife shield comprises a plurality of elongate knives which are arranged side-by-side upon a common support frame, the knives defining a generally cylindrical shield. Each knife is supported on the frame for movement in its longitudinal direction. At least one pair of diametrically opposed knives are coupled together, in the manner of a trackrod, for conjoint movement with respect to the longitudinal axis of the shield. During this movement the knives of the coupled pair concerned remain substantially parallel. The movement of the knives is used for controlling the direction of advance of the shield.