Joseph L Rasmussen

US Patent:

40120775, Mar 15, 1977

Filed:

Jul 2, 1976

Appl. No.:

5/702373

Inventors:

Wallace W. Roepke - Excelsior MN
David P. Lindroth - Apple Valley MN
Joseph W. Rasmussen - Minneapolis MN

Assignee:

The United States of America as represented by the Secretary of the
Interior - Washington DC

International Classification:

E21C 2724

US Classification:

299 76

Abstract:

The triangular-shaped rotary head mounted on an eccentrically driven shaft rotates at a low speed in a path determined by a ring/pinion gear ratio, such that cutting tools mounted on the apices of the triangular-shaped rotary head follow a square path entering the face of the coal seam to be cut at a top corner and making a long linear vertical cut at a constant depth of approximately one and one-half times the diameter of the rotary head greatly reducing dust generation and methane ignition potential, while increasing productivity.