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:
Oct. 10, 1978
Filed:
May. 12, 1977
Applicant:
Inventors:
Rolf Sander, Essen, DE;
Klaus Oberste-Beulmann, Sprockhovel, DE;
Assignees:
Gebr. Eickhoff, Maschinenfabrik und Eisengiesserei, m.b.H., Bochum, DE;
Bergwerksverband, G.m.b.H., Essen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21C / ;
U.S. Cl.
CPC ...
299 87 ; 175394 ;
Abstract
A screw-type cutter drum is provided having helical ribs on the drum body with cutter picks on the ribs and on the end of the drum. The cutter picks at the end of the drum are arranged in sets spaced apart to coincide with the ends of the ribs and the cutter picks of each set are equally spaced apart angularly and placed at different radial distances from the axis which decrease in the direction of rotation.