Method of Mechanized Construction for Earth Wire Under-Bracing and Extendable Excavating Unit for Auger Crane

A method of mechanized construction for earth wire under-bracing for a utility pole work, the method comprising the steps of:

• mounting excavation teeth having an excavating unit extendable/retractable in a transverse direction, on the excavating end portion of an auger for an auger crane,
• digging a burial hole having diameter of the earth wire under-bracing (33) and depth of 8-10th earth wire rod (34) by using the excavation teeth of the excavating unit whose extension width is adjusted according to the size of the earth wire under-bracing,
• removing soil and sand from an interference area of earth wire rod for burying the earth wire under-bracing in the burial hole,
• hanging a rope on a lower part of the earth wire under-bracing to be buried and lowering the earth wire under-bracing into the burial hole by the rope, and
• filling soil to the excavation hole, which the earth wire under-bracing is buried.

An extendable excavating unit for an auger crane for mechanized construction for earth wire under-bracing for utility pole work comprising:

• an excavating unit (20) mounted to the excavating end portion of the auger shaft (10) having a spiral auger scoop blade (11),
• a covering unit (27) which can slide along the supporting unit (24) and protruding excavation teeth (12) mounted on the covering unit (27),
• a body (21) coupled to an excavating end portion of the auger shaft (10), and the supporting unit (24) having a threaded pipe (22) inside and an adjusting bolt (26) fastened to the outer surface, so as to move transversely, is disposed on both sides of the body (21),
• a tubular adjusting unit (25) is inserted into the inner peripheral surface of the supporting unit (24),
• a slot (23) into which an end portion of the adjusting bolt (26) is inserted is formed on the outer peripheral surface of the adjusting unit (25), and
• a screw shaft (28) mated to the threaded pipe (22), penetrates from the outer end of the adjusting unit (25) so as to be screwed to the covering unit (27) having the excavation teeth (12), thereby coupling the screw shaft to the center of the covering unit (27),
• wherein said adjusting unit (25) and covering unit (27) slide along the supporting unit (24) according to the rotation of the screw shaft (28).