US Patent Issued to Robbins Mining on July 8 for "Tunnel boring machine for excavating semicircular-arched tunnels" (Washington Inventors)

ALEXANDRIA, Va., July 9 -- United States Patent no. 12,352,170, issued on July 8, was assigned to Robbins Mining Inc. (Solon, Ohio).

"Tunnel boring machine for excavating semicircular-arched tunnels" was invented by Bradley Dean Grothen (Renton, Wash.), Jay Michael McNeeley (Maple Valley, Wash.) and Stephen Mitchell Smading (Renton, Wash.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A Tunnel Boring Machine (TBM) with a circular cutting profile includes secondary cutterhead components that produce a semicircular-arched tunnel profile for use in underground mining and/or civil construction operations, e.g., for boring in material containing rocks with Unconfined Compressive Strength (UCS) of up to 200 MPA or...