US PATENT SUBCLASS 175 / 261
.~.~.~ With additional torque transmitting abutment on bit head and shaft

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use


175 /   HD   BORING OR PENETRATING THE EARTH

257  DF  TOOL REMOVABLE OR INSERTABLE THROUGH OR AROUND DRIVING OR DRIVEN SHAFT OR CASING {2}
258  DF  .~ Laterally shiftable cutter element movable through shaft {2}
260  DF  .~.~ Cutter element engages torque transmitting abutment on shaft when expanded {1}
261.~.~.~ With additional torque transmitting abutment on bit head and shaft

DEFINITION

Classification: 175/261

(under subclass 260) Apparatus in which the cutter element is carried by a bit head and the shaft and bit head are also provided with mutually engaging drive transmitting surfaces which transmit torque between the shaft and bit head.