Tunneling-Machine
Description:
Patent for a horizontal tunneling machine comprised of two different drill mechanisms - an inner and an outer drill stem - that could be operated separately and at different speeds, and adjusted while the drills were running. The drills make use of the tricone drill bit invented by Hughes in 1909, and could drill through hard rock more effectively than previous mechanisms.
Date:
unknown
Creator:
Hughes, Howard Robard
Item Type:
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Partner:
UNT Libraries Government Documents Department