PROPULSION CONSTRUCTION AND PROPULSION DEVICE FOR PROPULSION CONSTRUCTION

摘要

PURPOSE:To facilitate the formation of a curved excavated hole by repeating a push-in operation in which a bendable propelling unit into the earth and a pull-out operation in which the propelling unit is pulled out from the earth so as to propel the propelling unit. CONSTITUTION:A propelling pipe 1 is clamped by a clamping means 2, and a propelling unit 3 is pushed into the earth and is then operated. Next, when a second switch S2 is turned on so as to indicate that an attaching member 11 comes to the terminal end of a movement, the attaching member 11 is moved to the lower side in the propelling direction so as to effect a pull-out operation by which the unit 3 is pulled out from the earth while the clamping means 12 is left in the clamping condition. When a third switch S3 detects the presence of a magnet 14, the clamping means 12 is released so as to stop the pull-out operation. Further, a first switch S1 detects such a condition that the attaching member 11 reaches the starting end position of a movement, the attaching member 11 is changed over so that it can be again reciprocated.